Motor Record and related software
Tim Mooney, Joe Sullivan, Ron Sluiter
Contents
Overview
This documentation describes version 4.1 of the EPICS motor record, and
related EPICS software required to build and use it. Version 4.1
of the motor record is compatible with EPICS baseR3.13.1.1 and above.
The motor record is intended to support motors of all kinds, but currently
supports only the following variety of motor controllers (in addition to
Soft Channel support):
-
Oregon Microsystems VME8, VME44 and VME58 series.
-
Highland Technologies V540.
-
Newport MM3000, MM4000 and MM4005.
The record maintains two coordinate systems for motor position ("user"
and "dial" coordinates); displays drive and readback values; enforces limits
to motor motion and maintains those limits in both coordinate systems;
displays the states of limit switches; can use a home switch; optionally
takes out backlash in a user-defined direction; and provides a mechanism
by which the user and other EPICS records can recalibrate the motor position
in either coordinate system. The record also supports "tweak", "jog", and
"home" motions, and supports both absolute and relative motions in user
coordinates. Two "stop" switches are provided: a simple one for use by
other records and by channel-access clients, and a more versatile one for
interactive use.
Except where specified otherwise, fields associated with the motor position
and its derivatives take values in user-specified "engineering units",
such as degrees; the engineering unit name is contained in the field EGU.
Thus, generally, speeds are expressed in EGU's per second. Accelerations,
however, are expressed as the number of seconds taken to accelerate to
full speed. However, additional fields are provided so that the motor position
can be specified in steps and the speed in revolutions per second, and
so that the step size can be set by specifying the number of steps per
revolution and the number of EGU's per revolution.
The motor record can read motor position from the controller's readback
register or encoder register, or from any other EPICS record, via an EPICS
input link. While the motor is moving, the record can trigger an output
link periodically, to send readback information to other EPICS records.
When a complete motion (possibly including backlash takeout) is finished,
the record can trigger a forward link to process other EPICS records.
The motor record can force its drive fields to agree with its readback
fields, and it does so in a variety of circumstances (e.g., when the user
tells a motor to stop, and when a limit switch is hit). Therefore, if you
are driving the motor record's VAL or DVAL field with the output of another
record, and you want that record always to contain the same value as the
motor record, you must handle this behavior in the database. One way to
do this is to forward link the motor record to a soft analog output record,
and to cause that AO record to grab the motor record's VAL or DVAL field
and poke it into your record.
The motor record is unlike most other EPICS records in that its processing
is neither "synchronous" nor "asynchronous", as these terms are used in
the EPICS Record Reference Manual. Currently, the PACT field is always
FALSE after record processing has completed, even though a motor motion
may be in progress. This means the record always responds to channel-access
puts, and can be stopped or retargeted at any time. The record's forward
link is not executed until the motor has stopped and no motion requests
are pending.
Field Descriptions
In addition to fields common to all record types (see the EPICS
Record Reference Manual for these) the motor record has the fields
described below.
Alphabetical list of record-specific fields
NOTE: Hot links in this table take you only to the section in which
the linked item is described in detail. You'll probably have to scroll
down to find the actual item.
Name |
Access |
Prompt |
Data type |
Comment |
ACCL |
R/W |
Seconds to Velocity |
FLOAT |
acceleration time |
ATHM |
R |
At HOME |
SHORT |
uses the HOME switch |
BACC |
R/W |
BL Seconds to Veloc. |
FLOAT |
backlash acceleration time |
BDST |
R/W |
BL Distance (EGU) |
FLOAT |
backlash distance |
BVEL |
R/W |
BL Velocity (EGU/s) |
FLOAT |
backlash speed |
CARD |
R |
Card Number |
SHORT |
EPICS card # |
CBAK |
None |
Callback structure |
NOACCESS |
|
CNEN |
R/W |
Enable control |
RECCHOICE |
(0:"Disable", 1:"Enable") |
DCOF |
R/W |
Derivative Gain |
FLOAT |
|
DHLM |
R/W* |
Dial High Limit |
FLOAT |
|
DIFF |
R |
Difference dval-drbv |
DOUBLE |
|
DINP |
R/W |
DMOV Input Link |
INLINK |
|
DIR |
R/W* |
User Direction |
RECCHOICE |
(0:"Pos", 1:"Neg") |
DLLM |
R/W* |
Dial Low Limit |
FLOAT |
|
DLY |
R/W |
Readback settle time (s) |
FLOAT |
|
DMOV |
R |
Done moving to value |
SHORT |
The "done" flag |
DOL |
R |
Desired Output Loc |
INLINK |
only for closed-loop mode |
DRBV |
R |
Dial Readback Value |
DOUBLE |
|
DVAL |
R/W* |
Dial Desired Value |
DOUBLE |
|
EGU |
R/W |
Engineering Units |
STRING |
|
ERES |
R/W* |
Encoder Step Size (EGU) |
FLOAT |
|
FOF |
R/W |
Freeze Offset |
SHORT |
|
FOFF |
R/W |
Offset-Freeze Switch |
RECCHOICE |
(0:"Variable", 1:"Frozen") |
FRAC |
R/W |
Move Fraction |
FLOAT |
|
HHSV |
R/W* |
Hihi Severity |
GBLCHOICE |
HIGH |
R/W* |
High Alarm Limit |
FLOAT |
|
HIHI |
R/W* |
Hihi Alarm Limit |
FLOAT |
|
HLM |
R/W* |
User High Limit |
FLOAT |
|
HLS |
R |
At High Limit Switch |
SHORT |
|
HLSV |
R/W* |
HW Lim. Violation Svr |
GBLCHOICE |
|
HOMF |
R/W* |
Home Forward |
SHORT |
|
HOMR |
R/W* |
Home Reverse |
SHORT |
|
HOPR |
R/W |
High Operating Range |
FLOAT |
|
HSV |
R/W* |
High Severity |
GBLCHOICE |
|
ICOF |
R/W |
Integral Gain |
FLOAT |
|
INIT |
R/W |
Startup commands |
STRING |
|
JOGF |
R/W* |
Jog motor Forward |
SHORT |
careful! |
JOGR |
R/W* |
Jog motor Reverse |
SHORT |
careful! |
LDVL |
R |
Last Dial Des Val |
DOUBLE |
|
LLM |
R/W* |
User Low Limit |
FLOAT |
|
LLS |
R |
At Low Limit Switch |
SHORT |
|
LLSV |
R/W* |
Lolo Severity |
GBLCHOICE |
|
LOLO |
R/W* |
Lolo Alarm Limit |
FLOAT |
|
LOPR |
R/W |
Low Operating Range |
FLOAT |
|
LOW |
R/W* |
Low Alarm Limit |
FLOAT |
|
LRLV |
R |
Last Rel Value |
DOUBLE |
|
LRVL |
R |
Last Raw Des Val |
DOUBLE |
|
LSPG |
R |
Last SPMG |
RECCHOICE |
(See SPMG) |
LSV |
R/W* |
Low Severity |
GBLCHOICE |
|
LVAL |
R |
Last User Des Val |
DOUBLE |
|
LVIO |
R |
Limit violation |
SHORT |
|
MIP |
R |
Motion In Progress |
SHORT |
|
MISS |
R |
Ran out of retries |
SHORT |
|
MMAP |
R |
Monitor Mask |
ULONG |
|
MOVN |
R |
Motor is moving |
SHORT |
Don't confuse with DMOV |
MRES |
R/W* |
Motor Step Size (EGU) |
FLOAT |
|
MSTA |
R |
Motor Status |
ULONG |
|
NMAP |
R |
Monitor Mask |
ULONG |
|
OFF |
R/W |
User Offset (EGU) |
DOUBLE |
|
OMSL |
R/W |
Output Mode Select |
GBLCHOICE |
|
OUT |
R/W |
Output Specification |
OUTLINK |
|
PCOF |
R/W |
Proportional Gain |
FLOAT |
|
PERL |
R/W |
Periodic Limits |
RECCHOICE |
(0:"No", 1:"Yes") |
PDIF |
R |
Previous RDIF |
LONG |
POST |
R/W |
Post-move commands |
STRING |
|
PP |
R |
Post process command |
SHORT |
|
PREC |
R/W |
Display Precision |
SHORT |
|
PREM |
R/W |
Pre-move commands |
STRING |
|
RBV |
R |
User Readback Value |
DOUBLE |
|
RCNT |
R |
Retry count |
SHORT |
|
RDBD |
R/W |
Retry Deadband (EGU) |
FLOAT |
|
RDBL |
R |
Readback Location |
INLINK |
|
RDIF |
R |
Difference rval-rrbv |
LONG |
|
REP |
R |
Raw Encoder Position |
DOUBLE |
|
RES |
R |
Step Size (EGU) |
FLOAT |
|
RHLS |
R |
Raw High Limit Switch |
SHORT |
|
RINP |
R/W |
RMP Input Link |
INLINK |
|
RLLS |
R |
Raw Low Limit Switch |
SHORT |
|
RLNK |
R |
Readback OutLink |
OUTLINK |
|
RLV |
R/W* |
Relative Value |
DOUBLE |
|
RMP |
R |
Raw Motor Position |
DOUBLE |
|
RRBV |
R |
Raw Readback Value |
DOUBLE |
|
RRES |
R/W |
Readback Step Size (EGU) |
FLOAT |
|
RTRY |
R/W |
Max retry count |
SHORT |
|
RVAL |
R/W* |
Raw Desired Value |
DOUBLE |
|
RVEL |
R |
Raw Velocity |
LONG |
|
S |
R/W |
Speed (revs/sec) |
FLOAT |
|
SBAK |
R/W |
BL Speed (RPS) |
FLOAT |
|
SBAS |
R/W |
Base Speed (RPS) |
FLOAT |
|
SET |
R/W |
Set/Use Switch |
RECCHOICE |
(0:"Use", 1:"Set") |
SMAX |
R/W |
Max Velocity (RPS) |
FLOAT |
|
SPMG |
R/W* |
Stop/Pause/Move/Go |
RECCHOICE |
(0:"Stop", 1:"Pause", 2:"Move", 3:"Go") |
SREV |
R/W* |
Steps per Revolution |
LONG |
|
SSET |
R/W |
Set SET Mode |
SHORT |
|
STOO |
R/W |
STOP OutLink |
OUTLINK |
|
STOP |
R/W* |
Stop |
SHORT |
|
SUSE |
R/W |
Set USE Mode |
SHORT |
|
TDIR |
R |
Direction of Travel |
SHORT |
|
TWF |
R/W* |
Tweak motor Forward |
SHORT |
|
TWR |
R/W* |
Tweak motor Reverse |
SHORT |
|
TWV |
R/W* |
Tweak Step Size (EGU) |
FLOAT |
|
UEIP |
R/W* |
Use Encoder If Present |
RECCHOICE |
(0:"No", 1:"Yes") |
UREV |
R/W* |
EGU's per Revolution |
FLOAT |
|
URIP |
R/W* |
Use RDBL Link If Present |
RECCHOICE |
(0:"No", 1:"Yes") |
VAL |
R/W* |
User Desired Value |
DOUBLE |
|
VBAS |
R/W |
Base Velocity (EGU/s) |
FLOAT |
|
VELO |
R/W |
Velocity (EGU/s) |
FLOAT |
|
VERS |
R |
Code Version |
FLOAT |
e.g., "1.95" |
VMAX |
R/W |
Max Velocity (EGU/s) |
FLOAT |
|
VOF |
R/W |
Variable Offset |
SHORT |
|
Note: In the Access column above: |
R |
Read only |
|
R/W |
Read and write are allowed |
R/W* |
Read and write are allowed; write triggers record processing if the
record's SCAN field is set to "Passive." |
N |
No access allowed |
|
Calibration-related fields
Name |
Access |
Prompt |
Data type |
Comments |
DIR |
R/W* |
User Direction |
RECCHOICE |
(0:"Pos", 1:"Neg") |
User and dial values are related by the equation
userVAL = DialVAL * DIR + OFFset
This field is the "DIR" in the above equation. |
|
|
|
|
|
OFF |
R/W |
User Offset (EGU) |
DOUBLE |
User and dial coordinates can differ by a sign (the DIR field) and
an offset (OFF), according to the following equation:
userVAL = DialVAL * DIR + OFFset
This field is "OFFset" in the above equation. It is not normally written
to directly by the user. |
FOFF |
R/W |
Offset-Freeze Switch |
RECCHOICE |
(0:"Variable", 1:"Frozen") |
VOF |
R/W |
Variable Offset |
SHORT |
Set Offset switch (FOFF) to "Variable". |
FOF |
R/W |
Freeze Offset |
SHORT |
Set Offset switch (FOFF) to "Frozen". |
The user can cause the difference between user and dial
coordinates to remain fixed (i.e., the record will not change it, although
the user may) by setting FOFF to "Frozen." The fields VOF and FOF are intended
for use in backup/restore operations; any write to them will drive the
FOFF field to "Variable" (VOF) or "Frozen" (FOF). |
|
|
|
|
|
SET |
R/W |
Set/Use Switch |
RECCHOICE |
(0:"Use", 1:"Set") |
SSET |
R/W |
Set SET Mode |
SHORT |
Set Set/Use switch to "Set". |
SUSE |
R/W |
Set USE Mode |
SHORT |
Set Set/Use switch to "Use". |
SET is a toggle switch used in calibrating the motor's
user and dial positions:
When SET = 0 ("Use"), writes to the user-coordinate drive field (VAL)
cause the dial-coordinate drive field (DVAL) to change, and the motor to
move. Writes to the dial-coordinate drive field (DVAL) cause the user-coordinate
drive field (VAL) to change, and the motor to move.
When SET = 1 ("Set"), writes to the dial-coordinate drive field (DVAL)
and to the raw drive field (RVAL) cause a new raw motor position to be
loaded into the hardware without any change to the user-coordinate drive
field (VAL). Writes to other fields that would normally move the motor,
change the user-coordinate drive field (VAL), and the offset between user
and dial coordinates (the OFF field), with corresponding changes in the
user-coordinate limit fields (HLM and LLM). When the offset is frozen (FOFF=1),
writes to any drive field affect both user and dial values, and also load
the hardware position register. |
|
|
|
|
|
Motor-resolution fields
Name |
Access |
Prompt |
Data type |
Comments |
MRES |
R/W* |
Motor Step Size (EGU) |
FLOAT |
May be positive or negative |
SREV |
R/W* |
Steps per Revolution |
LONG |
Must be strictly positive |
UREV |
R/W* |
EGU's per Revolution |
FLOAT |
May be positive or negative |
MRES, and (SREV,UREV) represent two ways of specifying
the motor resolution--the distance or angle, in engineering units (EGU's),
associated with a single motor step. The equation relating these quantities
is "MRES = UREV/SREV". Initially, SREV has the value 200, the number of
full steps per revolution for most stepper motors, and the record never
changes this field. Only the user can change it.
When MRES is changed, the motor record sets UREV = MRES*SREV. When UREV
or SREV is changed, the motor sets MRES = UREV/SREV. In all cases, the
effect of a motor resolution change on the reported motor position depends
in a simple way on the value of the SET field:
If (SET = 1), new user and dial values (VAL, DVAL) are calculated from
the existing raw value (RVAL).
If (SET = 0), a new raw value is calculated from the existing dial
value.
The motor doesn't move in either case; neither does the actual motor
speed (in revolutions per second) change.
If either MRES or UREV is changed, motor speeds that are expressed in
engineering units per second (i.e., those whose names contain the letter
'V': VELO, BVEL, VMAX and VBAS) are automatically adjusted by the motor
record according to the following equations: VELO = UREV * S; BVEL = UREV
* SBAK; VMAX = UREV * SMAX; VBAS = UREV * SBAS. Motor speeds that
are expressed in revolutions per second (S, SBAK, and SBAS) are independent
of changes to MRES or UREV. In contrast, when SREV is changed, only
MRES is adjusted by the motor record, thus allowing all other fields to
remain unaffected.
Currently, changes to motor-resolution fields have no effect on the
values of limit fields (although they should).
MRES or UREV allow negative values so that the user/dial coordinate
systems can be configured to the opposite polarity of the motor controller's. |
|
|
|
|
|
ERES |
R/W* |
Encoder Step Size (EGU) |
FLOAT |
Encoder resolution: the distance or angle, in engineering units, associated
with a single encoder step. ERES may be positive or negative, but currently
it must have the same sign as MRES. |
RRES |
R/W |
Readback Step Size (EGU) |
FLOAT |
Readback-device resolution: the distance or angle, in engineering units,
associated with a unit change of the number retrieved via the readback-
location input link (RDBL). RRES may be either positive or negative. |
RES |
R |
Step Size (EGU) |
FLOAT |
The motor or encoder resolution, in engineering units, as selected
by the presence of an encoder supported by the hardware and by the switch
UEIP ("Use Encoder If Present"). If an encoder is present, and UEIP=1,
then RES will be set equal to ERES, otherwise RES will be set equal to
MRES. |
|
|
|
|
|
UEIP |
R/W* |
Use Encoder If Present |
RECCHOICE (0:"No", 1:"Yes") |
Switch: nonzero value tells the record to read the encoder (if the
hardware indicates an encoder is present) and to ignore the value read
back from the hardware's step-count register. |
URIP |
R/W* |
Use RDBL Link If Present |
RECCHOICE (0:"No", 1:"Yes") |
Switch: nonzero value tells the record to get the motor position from
the readback-location link (RDBL) (if it contains valid EPICS link information,
and if no error occurs in the attempt to read from the link) and to ignore
values read back from the hardware's step-count and encoder registers. |
These switches also direct the record to calculate destinations
in relative, rather than absolute, terms, since the ratio of encoder and
readback units to motor steps may not actually be constant. |
Motion-related fields
Name |
Access |
Prompt |
Data type |
Comments |
VMAX |
R/W |
Max Velocity (EGU/s) |
FLOAT |
Valid range; 0 <= VMAX. VMAX=0 disables maximum velocity range
checking. |
SMAX |
R/W |
Max Velocity (RPS) |
FLOAT |
Valid range; 0 <= SMAX |
VBAS |
R/W |
Base Velocity (EGU/s) |
FLOAT |
Valid range; 0 <= VBAS |
SBAS |
R/W |
Base Speed (RPS) |
FLOAT |
Valid range; 0 <= SBAS |
Range checking is done in such a way that any minimum
(i.e., VBAS/SBAS) or maximum (i.e., VMAX/SMAX) value entered is valid.
For example, if the minimum is entered and it exceeds the maximum, then
the maximum is set to the new minimum value. A VMAX value of zero
disables maximum velocity range checking.
Slew (VELO/S) and backup (BVEL/SBAK) velocity fields are silently forced
by the motor record to be within the range set by VMAX/SMAX and VBAS/SBAS,
inclusively.
Those who use both BURT and VMAX (i.e., nonzero VMAX) should insure
that VMAX and VBAS are placed before VELO and BVEL in their BURT request
files.
The intent of VBAS/SBAS is to prevent the motor from moving at speeds
slow enough to excite its resonance, which can cause the motor to miss
steps. The motor is expected to accelerate from a stand-still to VBAS in
one motor pulse. |
VELO |
R/W |
Velocity (EGU/s) |
FLOAT |
Valid range; VBAS <= VELO <= VMAX |
S |
R/W |
Speed (revs/sec) |
FLOAT |
Valid range; SBAS <= S
<= SMAX |
VELO is the speed, in engineering units per second, at
which the motor is move after the acceleration phase of a motion is finished.
S is the same speed expressed in revolutions per second. The record makes
sure that VELO and S are consistent, using the equation S = VELO/UREV. |
ACCL |
R/W |
Seconds to Velocity |
FLOAT |
The length, in seconds, of the acceleration and deceleration phases
of a motor motion. |
The motor record expects the hardware to produce a trapezoidal
speed profile. That is, the motor speed is expected to increase linearly
with time from the base speed, VBAS, to the full speed, VELO, in ACCL seconds.
At the end of a motion, the speed is expected to decrease similarly to
VBAS. |
|
|
|
|
|
BDST |
R/W |
BL Distance (EGU) |
FLOAT |
The signed distance, in dial coordinates, used for backlash takeout. |
The algorithm used in moves to a (dial-coordinate) position
called "TARGET" follows:
1) If the motor is to move a distance greater than the magnitude of
BDST, or if the motor is to move in a direction opposite to the sign of
BDST, then the motor will move first to position (TARGET-BDST), at an acceleration
specified by ACCL and speed VELO, and then to position TARGET, at an acceleration
specified by BACC and speed BVEL.
2) If the motor is to move a distance smaller than the magnitude of
BDST, and if the motor is to move in the same direction as the sign of
BDST, then backlash is assumed already to have been taken out, and the
motor will move to position TARGET at an acceleration specified by BACC
and speed BVEL. |
|
|
|
|
|
BVEL |
R/W |
BL Velocity (EGU/s) |
FLOAT |
SBAK |
R/W |
BL Speed (RPS) |
FLOAT |
BVEL is the speed, in engineering units per second, at
which the motor is move after the acceleration phase of a backlash-takeout
motion is finished. SBAK is the same speed expressed in revolutions per
second. Neither BVEL nor SBAK may be negative or zero. |
|
|
|
|
|
BACC |
R/W |
BL Seconds to Veloc. |
FLOAT |
The length, in seconds, of the acceleration and deceleration phases
of a backlash-takeout motion. See discussion of the acceleration field
ACCL for more specific information. |
|
|
|
|
|
FRAC |
R/W |
Move Fraction |
FLOAT |
This field supports closed-loop control of pathological
devices for which drive values are not expected to compare reproducibly
with readback values. (Inchworms and other friction-driven devices are
good examples: the number of steps taken by an inchworm motor is a very
poor indicator of the distance it has traveled.)
In a move from position CURRENT to position TARGET, the motor record
will ask hardware to move a distance FRAC*(TARGET-CURRENT). When that motion
is complete, the record will request a motion of FRAC*(remaining distance),
and so on until the target position has been reached. |
|
|
|
|
|
RDBD |
R/W |
Retry Deadband (EGU) |
FLOAT |
When the motor has finished a complete motion, possibly including backlash
takeout, the motor record will compare its current position with the desired
position. If the magnitude of the difference is greater than RDBD, the
motor will try again, as if the user had requested a move from the now
current position to the desired position. Only a limited number of retries
will be performed (see RTRY). |
RTRY |
R/W |
Max retry count |
SHORT |
The maximum number of times the motor record will try again to move
to the desired position. When the retry limit is reached, the motor record
will declare the motion finished. If the desired position was not reached,
the field MISS will be set to 1. |
Link-related fields
Name |
Access |
Prompt |
Data type |
Comments |
OUT |
R/W |
Output Specification |
OUTLINK |
If Soft Channel device support is specified, this field is an EPICS
link; each time DVAL is changed, device support puts DVAL to this link.
Otherwise, this field specifies the hardware to be controlled. |
RDBL |
R |
Readback Location |
INLINK |
This field specifies the field (of this or any other EPICS record)
from which the motor's current position is to be read when the field URIP
(Use Readback If Present) has the value "Yes" (1). If this field does not
contain a valid EPICS link, the URIP may as well have the value "No" (0).
If Soft Channel device support is specified, this field is monitored for
value changes by a CA event task. |
DOL |
R |
Desired Output Loc |
INLINK |
If this field contains a valid EPICS link, and the OMSL field has the
value "closed_loop" (1), then every time the the motor record is processed,
it will get a value for the VAL field from the link and move to that location,
ignoring all other drive fields. Closed-loop mode has not been tested extensively. |
OMSL |
R/W |
Output Mode Select |
GBLCHOICE |
(0:"supervisory", 1:"closed_loop")
If this field has the value "closed_loop" (1), and the field DOL contains
a valid EPICS link, then every time the the motor record is processed,
it will get a value for the VAL field from the link and move to that location,
ignoring all other drive fields. Closed-loop mode has not been tested extensively. |
RLNK |
R |
Readback OutLink |
OUTLINK |
If this field contains a valid EPICS link, then every time the motor
record is processed, it will put the (engineering-unit) readback value
RBV to that link. |
DINP |
R/W |
DMOV Input Link |
INLINK |
If Soft Channel device support is specified, the value specified by
this link is used to set the DONE bit in the MSTA field; which in turn
sets the DMOV field. |
RINP |
R/W |
RMP Input Link |
INLINK |
If Soft Channel device support is specified, the value specified by
this link is used to set the RMP field. |
STOO |
R/W |
STOP OutLink |
OUTLINK |
If Soft Channel device support is specified, a one is written to the
specified link each time the STOP_AXIS motor command is issued. |
Soft Channel Device Driver
The Soft Channel database links (i.e., DINP, RINP and STOO) are only processed
when the Soft Channel device driver is selected. These links are
ignored when using any other Motor Record device driver.
The input links (i.e., DINP, RDBL and RINP) are monitored for value
changes by a CA event task. Users must choose either a dial input
link (RDBL) or a raw input link (RINP), but not both. At this time, the
above links are not dynamically retargetable.
Note that JOG[F/R] does not work with the Soft Channel device driver. |
Limit-related fields
Name |
Access |
Prompt |
Data type |
Comments |
HLM |
R/W* |
User High Limit |
FLOAT |
The maximum allowed value of the VAL field. If HLM changes so that
VAL is no longer less than HLM, then the record will set the field LVIO
to 1. If the DIR field has the value "Pos", then HLM will always be consistent
with DHLM, otherwise HLM will always be consistent with DLLM. |
LLM |
R/W* |
User Low Limit |
FLOAT |
The minimum allowed value of the VAL field. If LLM changes so that
VAL is no longer greater than LLM, then the record will set the field LVIO
to 1. If the DIR field has the value "Pos", then LLM will always be consistent
with DLLM, otherwise LLM will always be consistent with DHLM. |
DHLM |
R/W* |
Dial High Limit |
FLOAT |
The maximum allowed value of the DVAL field. If DHLM changes so that
DVAL is no longer less than DHLM, then the record will set the field LVIO
to 1.. If the DIR field has the value "Pos", then DHLM will always be consistent
with HLM, otherwise DHLM will always be consistent with LLM. |
DLLM |
R/W* |
Dial Low Limit |
FLOAT |
The minimum allowed value of the DVAL field. If DLLM changes so that
DVAL is no longer greater than DLLM, then the record will set the field
LVIO to 1. If the DIR field has the value "Pos", then DLLM will always
be consistent with LLM, otherwise DLLM will always be consistent with HLM. |
LVIO |
R |
Limit violation |
SHORT |
A value of 1 indicates that the dial-value drive field, DVAL, or the
dial-value readback field, DRBV, is outside of the limits (DHLM, DLLM),
and this prevents the motor from moving. If the backlash distance, BDST,
is non-zero, it further restricts the allowable range of DVAL. When a JOG
button is hit, LVIO goes to 1 and stops the motor if/when DVAL gets to
within one second's travel time of either limit. |
PERL |
R/W |
Periodic Limits |
RECCHOICE |
(0:"No", 1:"Yes")
Not implemented. Originally intended to support periodic "limits" on
the VAL field (such as those associated with a rotation stage--e.g., [0...360]
or [-180...180]) independently of the actual soft limits HLM and LLM. |
HOPR |
R/W |
High Operating Range |
FLOAT |
Not used. See HLM and DHLM. |
LOPR |
R/W |
Low Operating Range |
FLOAT |
Not used. See LLM and DLLM. |
|
|
|
|
|
HLS |
R |
At High Limit Switch |
SHORT |
RHLS |
R |
Raw High Limit Switch |
SHORT |
If either of these fields is nonzero, then the motor is
at the positive-limit switch, where the positive sense is that of the user-coordinate
system for HLS, and that of the raw (step-number) coordinate system for
RHLS. |
|
|
|
|
|
|
|
|
|
|
LLS |
R |
At Low Limit Switch |
SHORT |
RLLS |
R |
Raw Low Limit Switch |
SHORT |
If either of these fields is nonzero, then the motor is
at the negative-limit switch, where the positive sense is that of the user-coordinate
system for LLS, and that of the raw (step-number) coordinate system for
RLLS. |
|
|
|
|
|
Command-button fields
Name |
Access |
Prompt |
Data type |
Comments |
SPMG |
R/W* |
Stop/Pause/Move/Go |
RECCHOICE |
(0:"Stop", 1:"Pause", 2:"Move", 3:"Go") |
This field is intended primarily for interactive use, and
normally has the value "Go."
If the user sets this field to "Stop," the motor will decelerate to
a stop, the VAL field will be set equal to the RBV field, and the DVAL
field will be set equal to the DRBV field. (These actions ensure that the
motor will not start moving again until a drive field is changed.) In any
case, the motor will not move while SPMG has the value "Stop" or "Pause."
If "SPMG" has the value "Move," the motor record will reset SPMG to
"Pause" when a motion completes. This behavior supports users who want
a motor to sit still until they say "Move", no matter what changes occur
in the drive fields. |
|
|
|
|
|
STOP |
R/W* |
Stop |
SHORT |
When this field is set to 1, the record will immediately
reset it to 0, and the motor will decelerate to a stop. When the motor
has stopped, VAL will be set equal to RBV, and DVAL will be set equal to
DRBV. (This ensures that the motor will not start moving the next time
the record is processed, unless a drive field is explicitly changed. If
you want the motor to pause, use the SPMG field.) |
|
|
|
|
|
HOMF |
R/W* |
Home Forward |
SHORT |
HOMR |
R/W* |
Home Reverse |
SHORT |
When one of these fields is set to 1, the motor will decelerate
to a stop if already moving, move in the indicated direction (in dial
coordinates) at the acceleration specified by ACCL and a speed of 1000
motor pulses per second, until the hardware detects the "home" switch has
become active. Then the hardware will do something hardware dependent in
response to its "home" command, if any. (The OMS hardware causes the motor
to decelerate to a stop.) When the motor stops, the VAL field will be set
equal to the RBV field, and the DVAL field will be set equal to the DRBV
field. These fields can be set to 1, but setting either field to
0 results in an error. The record sets HOM[F/R] to zero when the
homing procedure is either completed or aborted. |
|
|
|
|
|
JOGF |
R/W* |
Jog motor Forward |
SHORT |
JOGR |
R/W* |
Jog motor Reverse |
SHORT |
When one of these fields is set to 1, the motor will decelerate
to a stop if already moving, and move in the indicated direction (in user
coordinates) at an acceleration specified by ACCL and speed VELO, until
the field goes to 0. Then the motor will set VAL to RBV and DVAL to DRBV,
decelerate to a stop, and execute a (backlash-corrected, if BDST is nonzero)
move to the position at which the field went to 0.
These fields are dangerous when used over channel access, because the
motor does not stop moving until a second message is received. If a very
busy network should cause that second message to be lost, the motor will
travel to its limit switch or hard stop. |
|
|
|
|
|
TWF |
R/W* |
Tweak motor Forward |
SHORT |
TWR |
R/W* |
Tweak motor Reverse |
SHORT |
When one of these fields is set to 1, the record will immediately
reset it to 0, and the motor will move (with backlash takeout if BDST is
nonzero) by a distance TWV (in user coordinates) at the acceleration specified
by ACCL and at speed VELO. |
TWV |
R/W* |
Tweak Step Size (EGU) |
FLOAT |
This field contains the distance the motor is to move in response to
the TWF and TWR buttons. |
Drive fields
Name |
Access |
Prompt |
Data type |
Comments |
VAL |
R/W* |
User Desired Value |
DOUBLE |
This is the desired position in user coordinates. When this field is
written to, DVAL and RVAL will be changed correspondingly, and the motor
will move (with backlash takeout if BDST is nonzero) to the newly written
position. |
DVAL |
R/W* |
Dial Desired Value |
DOUBLE |
This is the desired position in dial coordinates. When this field is
written to, VAL and RVAL will be changed correspondingly, and the motor
will move (with backlash takeout if BDST is nonzero) to the newly written
position. |
RVAL |
R/W* |
Raw Desired Value |
DOUBLE |
This is the desired position in raw coordinates. When this field is
written to, VAL and DVAL will be changed correspondingly, and the motor
will move (with backlash takeout if BDST is nonzero) to the newly written
position. |
RLV |
R/W* |
Relative Value |
DOUBLE |
When this field is changed, its value will be added to VAL, the field
itself will immediately be reset to 0, and the motor record will behave
as though the VAL field had been changed directly. |
Status/readback fields
Name |
Access |
Prompt |
Data type |
Comments |
RBV |
R |
User Readback Value |
DOUBLE |
The current motor position, in user coordinates, from the motor hardware
(default), or from the encoder supported by the motor-controller hardware
(if UEIP is nonzero), or from the readback link RDBL (if URIP is nonzero). |
DRBV |
R |
Dial Readback Value |
DOUBLE |
The current motor position, in dial coordinates, from the motor hardware
(default), or from the encoder supported by the motor-controller hardware
(if UEIP is nonzero), or from the readback link RDBL (if URIP is nonzero). |
DMOV |
R |
Done moving to value |
SHORT |
This field is set to 0 when the motor record begins a motion,
and remains 0 through any retries and backlash corrections that may be
required until the motor record has completely finished that motion, whereupon
the field is set to 1. DMOV is guaranteed to execute and post a 1/0/1 pulse
when the motor is commanded to move--even if no motion actually occurs
because the motor was commanded to move to its current position. |
MOVN |
R |
Motor is moving |
SHORT |
This field is set to 1 while the record believes that the motor actually
is moving. This field is not the inverse of DMOV, since it may go to zero
during a complex motion, if that motion includes a momentary stop. |
DLY |
R/W |
Readback settle time (s) |
FLOAT |
Delay (in seconds) the time between motor controller done and motor
record done (i.e., DMOV). |
DIFF |
R |
Difference dval-drbv |
DOUBLE |
DIFF is the difference, in engineering units, between the
desired motor position, and the readback device's report of the current
position. RDIF is the same difference in "raw" units (normally, steps). |
RDIF |
R |
Difference rval-rrbv |
LONG |
RRBV |
R |
Raw Readback Value |
DOUBLE |
The current position of the motor, encoder, or readback link, as received
from whatever source has been selected to provide position information.
The units associated with this field depend on the source. |
RMP |
R |
Raw Motor Position |
DOUBLE |
The contents of the hardware's step-count register. This field contains
the same information as the dial value, but in steps, rather than in engineering
units. |
REP |
R |
Raw Encoder Position |
DOUBLE |
The contents of the hardware's encoder-count register. Ideally, this
field contains the same information as the dial value, but in encoder counts,
rather than in engineering units. |
MSTA |
R |
Motor Status |
ULONG |
The motor status as received from the hardware. The MSTA bits
are defined as follows:
-
DIRECTION: (0:Negative, 1:Positive)
-
DONE: motion is complete.
-
OVERTRAVEL: a limit switch has been hit.
-
HOMELS: state of the home limit switch.
-
Unused
-
POSITION: closed-loop position control is enabled.
-
Unused
-
HOME: if at home position.
-
PRESENT: encoder is present.
-
PROBLEM: driver stopped polling.
-
MOVING: non-zero velocity present.
-
GAIN_SUPPORT: motor supports closed-loop position control.
|
TDIR |
R |
Direction of Travel |
SHORT |
The direction in which the motor is currently traveling (or was most
recently traveling), as received from the hardware. If 0, the raw readback
value should be decreasing. |
ATHM |
R |
At HOME |
SHORT |
The state of the hardware's "home" switch. If 1, the motor has hit
the switch. |
RCNT |
R |
Retry count |
SHORT |
The number of times the motor record has detected failure of the motor
to land within the retry-deadband distance of the desired position. |
MISS |
R |
Ran out of retries |
SHORT |
If 1, the motor has failed to land on the desired position more than
the allowed number of times. This field will be reset the next time the
motor succeeds in reaching the desired position. |
RVEL |
R |
Raw Velocity |
LONG |
Speed in steps per second that the motor actually is moving. |
Servo fields
PID related record fields accept only normalized
values (i.e., 0.0 <= value <= 1.0). Before sending them to
the motor controller, device support scales the record fields to valid
motor controller parameters,. Let the motor controller PID parameters
be represented by CKP, CKI and CKD; then the PID coefficients are converted
from motor record fields to controller parameters as follows:
For the MM4000; CKP = PCOF, CKI = ICOF and CKD = DCOF.
For all OMS controllers; CKP = 1999.9 * PCOF, CKI = 1999.9 *
ICOF, CKD = 1999.9 * DCOF.
Note the following:
-
When commanded to move the OMS control law is a PD loop, when it is holding
a position it is a PID loop.
-
The Proportional Gain cannot be turned off (i.e., set to zero) in an OMS
controller. The minimum value is PCOF = 0.00005 (CKP = 0.1).
If the user sets PCOF < 0.00005 for an OMS controller, device support
silently resets it to it's minimum value of 0.00005.
|
Name
|
Access
|
Prompt
|
Data type
|
Comments
|
CNEN |
R/W |
Enable control |
RECCHOICE |
(0:"Disable", 1:"Enable") Enable/Disable closed-loop position
control. This field is active only if the GAIN_SUPPORT bit in the
MSTA is true. This field is set by both the user and device support.
CNEN is set to Disable by device support when it detects a motion
controller error; e.g. maximum following error exceeded. |
PCOF |
R/W |
Proportional Gain |
FLOAT |
Valid range; 0.0 <= PCOF <= 1.0 |
ICOF |
R/W |
Integral Gain |
FLOAT |
Valid range; 0.0 <= ICOF <= 1.0 |
DCOF |
R/W |
Derivative Gain |
FLOAT |
Valid range; 0.0 <= DCOF <= 1.0 |
Alarm fields
Name |
Access |
Prompt |
Data type |
Comments |
HIHI |
R/W* |
Hihi Alarm Limit |
FLOAT |
LOLO |
R/W* |
Lolo Alarm Limit |
FLOAT |
HIGH |
R/W* |
High Alarm Limit |
FLOAT |
LOW |
R/W* |
Low Alarm Limit |
FLOAT |
HHSV |
R/W* |
Hihi Severity |
GBLCHOICE |
Not used. |
LLSV |
R/W* |
Lolo Severity |
GBLCHOICE |
Not used. |
HSV |
R/W* |
High Severity |
GBLCHOICE |
Not used. |
LSV |
R/W* |
Low Severity |
GBLCHOICE |
Not used. |
HLSV |
R/W* |
HW Limit Switch Violation Severity |
GBLCHOICE |
Miscellaneous fields
Name |
Access |
Prompt |
Data type |
Comments |
PREC |
R/W |
Display Precision |
SHORT |
The number of digits to the right of the decimal that are to be displayed
by MEDM and other channel-access clients. |
EGU |
R/W |
Engineering Units |
STRING |
String sent to channel-access clients who ask for engineering units. |
VERS |
R |
Code Version |
FLOAT |
Version number of the recMotor.c code. |
CARD |
R |
Card Number |
SHORT |
For VME based devices (i.e., OMS VME8/44, OMS VME58 and V544) this
is the VME card number, derived from the output link. Cards are numbered
from zero according to their VME addresses. Oregon Microsystems series
VME8 and VME44 cards occur in the same series, since they are handled by
the same driver. Oregon Microsystems VME58 cards are numbered separately,
as are Highland Technology V540 cards. This field is set to -1 for
non-VME based device/drivers. |
Command Primitives
The following three fields comprise the Command Primitives feature.
The command primitive record fields are available to the user to send ASCII
command primitives to the motor control board at fixed, predefined, times.
Each of the fields is defined as a character string. Consult the
motor controller manual for command protocols. No error checking
is done by the motor record or the device driver to insure that the command
strings are valid. Each field is terminated by the device
driver according to the command protocol. Command primitives that
result in a response from the motion control board are valid, but the response
is not processed. This feature is currently only available with OMS
VME8/44/58 or Newport MM4000 device support.
Device Directives
-
Valid only in the INIT field.
-
Must be identified by the following;
-
First character of INIT string must be a '@'.
-
One or more characters followed by a terminating '@'; i.e., device directives
must have nonzero length.
-
A valid device directive; currently, only "DPM_ON".
-
INIT strings are stripped of valid device directives (including @'s) and
tested for nonzero length before being sent to the controller. For
example, given the INIT string, "@DPM_ON@HE", the device directive @DPM_ON@
is stripped out before HE is sent to the controller.
Driver Power Monitoring
-
This feature is only available with the OMS VME58 device support.
-
The 8 User I/O signals are assigned to the 8 possible VME58 axes as follows:
User I/O #0 <> X axis
" " 1 <> Y
"
........................................
" " 7 <> S
"
-
Drive-power monitoring defaults to disabled at boot-up. Request enabling
drive-power monitoring by entering the device directive "@DPM_ON@" command
into the motor record initialization field (i.e., INIT). The INIT
field is processed at record initialization (i.e., bootup), hence if there
are no errors, drive-power monitoring will be enabled after the next bootup.
-
Whenever a request is made to enable drive-power status monitoring, an
error check is made (using the VME58 "RB" command) to verify that the User
I/O has been configured as an input. The following message will appear
in the error log if a configuration error is detected; "Invalid VME58 configuration;
RB = 0x####", where "####" is the VME58's response to the RB command.
-
When drive-power status monitoring is enabled and a power failure is detected,
the device driver will respond by activating the the RA_OVERTRAVEL bit
in the MSTA. This results in either HLS or LLS being activated depending
on the DIR field. In addition, the following message will appear in the
error log; "Drive power failure at VME58 card#?? motor#??".
|
INIT |
R/W |
Startup commands |
STRING |
Sent at record initialization. |
PREM |
R/W |
Pre-move commands |
STRING |
Sent before every command string that causes motion. |
POST |
R/W |
Post-move commands |
STRING |
Sent after a complete motion is finished or when an overtravel limit
switch is detected. |
Private fields
Name |
Access |
Prompt |
Data type |
Comments |
CBAK |
None |
Callback structure |
NOACCESS |
|
LVAL |
R |
Last User Des Val |
DOUBLE |
LDVL |
R |
Last Dial Des Val |
DOUBLE |
LRVL |
R |
Last Raw Des Val |
DOUBLE |
LRLV |
R |
Last Rel Value |
DOUBLE |
PDIF |
R |
Previous RDIF |
LONG |
PP |
R |
Post process command |
SHORT |
MIP |
R |
Motion In Progress |
SHORT |
MMAP |
R |
Monitor Mask |
ULONG |
NMAP |
R |
Monitor Mask |
ULONG |
LSPG |
R |
Last SPMG |
RECCHOICE |
(see SPMG) |
Files, device support
The following table briefly describes all of the files required to implement
and use the motor record. The reader is assumed to be familiar with the
EPICS
Application Source/Release Control document which describes how to
build an EPICS application tree into which these files are to be placed,
and how to run "makesdr" and "gnumake" to build the record support. These
files can all be obtained from the EPICS
Software Distribution (in the custom-software
section).
SOURCE CODE
files to be placed in <top>/<app>App/src/ |
motorRecord.dbd |
Database Definition file for motor record. |
motorRecord.c |
Record support for the motor record |
motor.h |
Header included by all .c files |
|
|
motordevCom.c |
Device support common to all motor Record device drivers. |
motordevCom.h |
Device support header file. |
motordrvCom.c |
Driver support common to all motor Record device drivers. |
motordrvCom.h |
Driver support header file. |
motordrvComCode.h |
Local variables common to all motor Record drivers. |
|
NOTE: All of the above files are required for any and all motor Record
device drivers. |
|
|
devOmsCom.c |
Device support common to all Oregon Microsystems device drivers. |
devOmsCom.h |
Device support header file common to all Oregon Microsystems device
drivers. |
drvOmsCom.h |
Driver support header file common to all Oregon Microsystems device
drivers. |
|
NOTE: The above files are required for any and all Oregon Microsystems
device drivers. |
|
|
devOms.c |
Device support for Oregon Microsystems VME8 and VME44 series boards |
drvOms.c |
Driver for Oregon Microsystems VME8 and VME44 series boards |
drvOms.h |
Header included by devOms.c and drvOms.c |
|
|
devOms58.c |
Device support for Oregon Microsystems VME58 series boards |
drvOms58.c |
Driver for Oregon Microsystems VME58 series boards |
drvOms58.h |
Header included by devOms58.c and drvOms58.c |
|
|
devV544.c |
Device support for Highland Technology boards. |
drvV544.c |
Driver for Highland Technology boards. |
drvV544.h |
Header included by devV544.c and drvV544.c |
|
|
drvMMCom.h |
Common header included by all Newport Motion Master device drivers. |
gpibIO.h |
GPIB communication include file. |
gpibIO.c |
GPIB interface via Hideos. |
serialIO.h |
Serial communication include file. |
serialIO.cc |
Serial communication interface via Hideos. |
|
NOTE: The above files are required for any and all Newport Motion Master
device drivers. |
devMM3000.c |
Device support for Newport MM3000. |
drvMM3000.c |
Driver for Newport MM3000. |
devMM4000.c |
Device support for Newport MM4000. |
drvMM4000.c |
Driver for Newport MM4000. |
|
|
|
|
devSoft.c |
Soft Channel device support. |
devSoftAux.c |
Soft Channel device support (Note: CA and record access code cannot
both reside in the same file; each defines (redefines) the DBR's.
Hence, functions are split between this and the above file base on whether
they are record oriented (devSoft.c) or CA oriented (devSoftAux.c). |
devSoft.h |
Header included by devSoft.c and devSoftAux.c |
|
|
Makefile.Vx |
This file is not included in the distribution. However, the user must
edit this file and add lines similar to the following:
MOTOR_OBJS = motorRecord.o devOms.o drvOms.o devOms58.o drvOms58.o
LIBNAME = mylib.o
LIBOBJS = $(MOTOR_OBJS) $(other objects here)
|
ASCII FILES
files to be placed in <top>/cat_ascii/ |
motorRecord.ascii |
This file defines all of the fields for the motor record. |
choiceRecMotor.ascii |
This file defines all of the choice values for the motor record. |
choiceMotor.h |
This file is included by choiceRecMotor.ascii and by recMotor.c. |
choiceRec.ascii |
This file is not included in the distribution. However, the user must
edit this file and add the line:
#include <choiceRecMotor.ascii>
|
dbRecType.ascii |
This file is not included in the distribution. However, the user must
edit this file and add the line:
"motor"
|
devSup.ascii |
This file is not included in the distribution. However, the user must
edit this file and add the following lines:
! Device Support for motor record
"motor" VME_IO "devOMS" "OMS VME8, VME44"
"motor" VME_IO "devOms58" "OMS VME58"
"motor" VME_IO "devV544" "Highland V544"
|
drvSup.ascii |
This file is not included in the distribution. However, the user must
edit or create this file and add the following lines:
! Driver support for the OME VME58 motor controller
"drvOms58"
|
MEDM DISPLAY SCREENS
files to be placed in <top>/<app>App/op/adl/ |
motorx.adl |
Small motor-control screen |
motorx_tiny.adl |
Tiny motor-control screen |
motorx_more.adl |
Medium motor-control screen |
motorx_setup.adl |
Setup screen for a single motor |
motorx_all.adl |
Debug screen for a single motor |
These files build medm screens to access the motor
record. To use one of them from the command line, type, for example
medm -x -macro "P=XXX:,M=m1" motorx.adl
where XXX:m1 is the name of a motor record in an IOC.
These files can also be used as related displays from other medm
screens by passing the argument "P=XXX:,M=m1". |
EPICS STARTUP FILES
files to be placed in <top>/ioc/ioc<name>/ |
st.cmdmv167 |
Startup script |
A sample startup script, containing excerpts relevant to
motors, is included in the distribution. Here is an annotated copy:
#######################################################################
# vxWorks startup script to load and execute system (iocCore) software.
Load standard EPICS software
# the following should be loaded first - BEGIN
ld < targetmv167/iocCore
ld < targetmv167/drvSup
ld < targetmv167/devSup
ld < targetmv167/recSup
# the following should be loaded first - END
Load custom EPICS software (including motor support)
ld < ../../stdApp/src/O.mv167/stdlib.o
Motor-related debug switches
recMotordebug = 0
#OMS vme8/vme44 debug switches
devOMSdebug = 0
drvOMSdebug = 0
#OMS vme58 debug switches
devOms58debug = 0
drvOms58debug = 0
#Highland Technology V544 debug switches
devV544ebug = 0
drvV544debug = 0
Motor-related databases
# load this before loading any databases
dbLoad "../../default.dctsdr"
#allstop
dbLoadRecords("../../stdApp/gDb/allstop.db","P=tmm:")
#motors
dbLoadRecords("../../stdApp/gDb/m16.db","P=tmm:")
Specify motor-controller board address, interrupt
vector, etc.
omsSetup(nCards, Unused, baseAddress,
intVectBase, intLevel, pollRate)
oms58Setup(nCards, Unused, baseAddress, intVectBase, intLevel,
pollRate)
v544Setup(nCards, nAxes, baseAddress, intVectBase,
intLevel, pollRate)
MM4000Setup(nCards, Unused,
pollRate)
MM4000Config(card#, portType, GPIB link or hideos_card#, GPIB address
or hideos_task name) |
nCards |
the actual number of cards may be less, but not greater than this |
nAxes |
the maximum number of motor axes controlled by any one card |
baseAddress |
the base address of the first card of a series. This must agree with
address jumpers on the actual card(s).
OMS VME8, VME44, and VMEX cards are all of one series, with a base address
in the short address space, on a 16-byte (0x10) boundary. (I.e., these
cards require 16 bytes each, and must all be addressed contiguously as,
e.g., 0xFC00, 0xFC10).
OMS VME58-x cards are in their own series, also in the short address
space, on a 4k-byte (0x1000) boundary.
Highland Technology V544 cards are in their own series, in the short
address space, on a 128-byte (0x80) boundary. |
intVectBase |
the interrupt vector that will be loaded into the first card of a series.
Succeeding cards will be loaded with intVectBase+1, intVectBase+2, etc.
Set to "0" to disable interrupt generation; otherwise, stay in the range
[64..255]. |
intLevel |
the VME-interrupt level (in [1..6]) the cards will use. This must agree
with jumper settings on the cards. |
pollRate |
the rate (in Hz.) at which the driver will interrogate a card when
one of its motors is moving. This is also the rate at which channel-access
monitors will be posted; to avoid saturating the network with motor-readback
information, don't set pollRate much higher than 10 Hz. pollRate must be
in the range [1..60]. |
portType |
0 - GPIB_PORT or 1 - RS232_PORT |
# OMS VME8, VME44, VMEX driver setup parameters:
omsSetup(5, 8, 0xFC00, 180, 5, 10)
# OMS VME58 driver setup parameters:
oms58Setup(5, 8, 0x2000, 190, 5, 10)
# Highland Technology V544 driver setup parameters:
v544Setup(5, 4, 0xDD00, 200, 5, 10)
Start EPICS
iocInit
|
BACKUP/RESTORE (BURT) REQUEST FILES
files to be placed in <top>/<app>App/op/burt/ |
settings.req |
sample request file to save settings of all motors. Edit this file,
supplying names of the motor records whose settings you want saved. (The
sample file also saves the states of other records in the sample database,
m16.db, that enable or disable the motor records.) |
yyMotorSettings.req |
save settings of a specified motor. This file is #include'd
(once for each motor) by settings.req. |
positions.req |
sample request file to save positions of all motors. Edit this file,
supplying names of the motor records whose positions you want saved. |
yyMotorPositions.req |
save position of a specified motor, This file is #include'd
(once for each motor) by positions.req. |
These files tell the backup/restore tool how to save motor
settings and positions. To use them from the command line, type, for example
burtrb -f settings.req -o myMotorSettings.snap
burtrb -f positions.req -o myMotorPositions.snap
To restore the motor settings and positions saved by the above commands,
type
burtwb -f myMotorSettings.snap
burtwb -f myMotorPositions.snap
|
Restrictions
You must not change the motor resolution while the motor is moving,
but the record currently does not defend itself against this.
There is no way to ask for a reading of the motor's position register,
encoder, or limit switches. These are read only while the motor is moving.
Because of the way limit-switch information is conveyed by the OMS hardware,
the motor record cannot know the states of both limit switches at the same
time. It only knows the state of the switch toward which the motor is moving.
If a move is requested while the motor already is in motion, the original
move will still receive a (useless) backlash correction.
Changing MRES (the motor resolution) should change VELO (the speed in
engineering units per second), and leave S (the speed in revolutions per
second) unchanged. Currently, neither VELO nor S appears to change, but
the record behaves as though S had been changed to agree with VELO. A similar
thing happens with SBAK and SBAS.
Examples
Command Primitives
This example assumes the controller is an MM4000 and that only one motor
in the controller is moved at a time (MM4000 power on/off effects all motors).
If the user wishes the system to perform as follows:
-
Boot-up with motor power off.
-
Turn motor power on before motor motion.
-
Turn motor power off after motor motion.
Then set fields as follows:
-
INIT = "MF"
-
PREM = "MO"
-
POST = "MF"
Soft Channel
The following is a simple example of using soft channel device support
to allow the user to transform rotary position commands into linear moves.
This example assumes the system consist of a linear stage driving a tangent
arm. The user commands the system in terms of the angle the arm makes
with the vertical. The database converts this angle into a linear
position along an axis that is one meter perpendicular to the center of
rotation.
The following database implements the system described above.
The database consist of four records:
-
rotary - a soft motor record where the user issues angular
position commands in degrees.
-
convertDriveValue - a calcout record that converts the commanded
position from degrees to mm.
-
linear - a hard motor record using Oms58 device support
that accepts linear position commands in mm.
-
convertReadbackValue - calcout record that converts the feedback
position from mm
to
degrees.
Note the following concerning the example database and Soft Channel device
support:
-
Jogging a soft channel motor record is not supported.
-
In the convertReadbackValue record, CP is required in the INPA field
to get continuous readback updates to the rotary record. Otherwise,
the rotary record will only update at the end of a move.
-
The convertDriveValue record converts rotary's DVAL field
from degrees to radians, takes the tangent, converts from meters to millimeters
and finally, sends this value to linear's DVAL field.
-
The convertReadbackValue record converts linear's DRBV field
from millimeters to meters, takes the inverse tangent and finally, converts
from radians to degrees.
grecord(motor,"$(user):rotary")
{
field(DTYP,"Soft Channel")
field(OUT,"$(user):convertDriveValue.A PP
MS")
field(RDBL,"$(user):convertReadbackValue.VAL
NPP MS")
field(URIP,"Yes")
field(STOO,"$(user):linear.STOP PP MS")
field(DINP,"$(user):linear.DMOV NPP MS")
field(MRES,"0.001")
field(RRES,"1.000")
field(PREC,"3")
field(DHLM,"45")
field(DLLM,"-45")
field(TWV,"5")
field(RTRY,"0")
field(EGU,"deg.")
} |
grecord(motor,"$(user):linear")
{
field(DTYP,"OMS VME58")
field(VBAS,"1.0")
field(VELO,"25.0")
field(OUT,"#C0 S0 @")
field(MRES,"0.001")
field(PREC,"3")
field(DHLM,"1000")
field(DLLM,"-1000")
field(RTRY,"0")
field(TWV,"1")
field(EGU,"mm.")
} |
grecord(calcout,"$(user):convertDriveValue")
{
field(DESC,"Convert rotary to linear")
field(CALC,"TAN(A / 57.296) * 1000")
field(OUT,"$(user):linear.DVAL PP MS")
} |
grecord(calcout,"$(user):convertReadbackValue")
{
field(DESC,"Convert linear to rotary")
field(CALC,"ATAN(A / 1000) * 57.296")
field(INPA,"$(user):linear.DRBV CP MS")
} |
Design Decisions
This section of the document is an attempt to record the reasoning behind
recent motor record design decisions.
Motor Controller Travel Limits
For those motor controllers that provide their own internal software travel
limits (e.g., MM4000), the motor record will only allow the user to set
dial travel limits (i.e., D[H/L]LM) that are within the controller's travel
limit range, inclusively. In making this design decision it was assumed
that an expert user would enter the controller travel limits (possibly,
through a front panel user interface) that would protect other users from
reaching the hard travel limits. Controllers with their own travel
limits that are commanded to move outside their valid range respond with
an error. Hence, there is no utility in allowing the dial travel
limits outside the controller's range.
Separate EGU's and MRES's between Controller and Motor Record
Device driver support for controllers that have characteristics different
from the OMS controllers, such as the Newport MM4000, has raised new issues.
One of these issues is whether or not the motor record should set it's
EGU and MRES fields from the controller's values. We think it should
not.
Background: The MM4000 is a stand-alone controller with it's own front
panel, non-volatile memory and power supply. The user can configure
the MM4000 entirely from the front panel; including which engineering units
will be displayed on the front panel. Once engineering units are
selected, these same units will be used by the MM4000 when communicating
with a host system (i.e., EPICS). Since a host can query the MM4000
for both the controller's engineering units and it's positioning resolution,
it is possible to have the motor record's EGU and MRES fields automatically
set based on values stored in the MM4000 controller, but we decided not
to do this.
To maximize flexibility, we decided to keep these characteristics separate
between the motor record and the controller. This decision allows
the motor record EGU field (and consequently, MRES) to be set to an application
specific value (e.g., kV) that is not supported by the motor controller.
Suggestions and comments to:
Ron Sluiter : ([email protected])
Tim Mooney : ([email protected])
Joe Sullivan : ([email protected])
Last modified: July 12, 1999