NB: This manual documents a 20+ year old version of EPICS, see here for the EPICS 7 Record Reference documentation.
EPICS Record Reference Manual
scan parameters
trigger parameters
pulse parameters
output parameters
operator display parameters
run-time parameters
Hardware
or Software
. If Hardware
, then the triggers are device dependent, and the HGV field determines gating control, HGV being device dependent.
If the user configures GTYP to be software, then the soft gate value (SGV) field provides gating control. This field has the same possible values as HGV, Active
and Inactive
, triggering a pulse when Active
, or not triggering a pule when Inactive
. The SGV value can be retrieved from the location specified in the Soft Gate Location (SGL) field, which must be a database link.
The CEDG, CTYP, ECS, and ECR field may not have significance for all device support modules. For the modules they apply to, they control the timing of pulses. The CEDG field determines whether clock timing occurs on the rising edge or falling edge of a signal. It has two choices: Rising Edge
or Falling Edge
. The CTYP field determines whether the timing is controlled externally or internally and has two choices: Internal
and External
. The ECS and ECR fields have significance only if CTYP specifies External
.
Field | Summary | Type | DCT | Initial | Access | Modify | Rec Proc Monitor | PP |
---|---|---|---|---|---|---|---|---|
GTYP | Gate Type | RECCHOICE | Yes | 0 | Yes | Yes | No | No |
HGV | Hardware Gate Value | SHORT | Yes | 0 | Yes | Yes | No | No |
SGL | Soft Gate Location (Input Link) | INLINK | Yes | 0 | No | No | N/A | No |
SGV | Soft Gate Value | RECCHOICE | Yes | 0 | Yes | Yes | No | No |
CTYP | Clock Type | RECCHOICE | Yes | 0 | Yes | Yes | No | No |
CEDG | Clock Signal Edge | RECCHOICE | Yes | 0 | Yes | Yes | No | No |
ECS | External Clock Source | SHORT | Yes | 0 | Yes | Yes | No | No |
ECR | External Clock Rate, in Hz | DOUBLE | Yes | 0 | Yes | Yes | No | No |
Seconds
, Milliseconds
, Microseconds
, Nanoseconds
, or Picoseconds
.
Field | Summary | Type | DCT | Initial | Access | Modify | Rec Proc Monitor | PP |
---|---|---|---|---|---|---|---|---|
UNIT | Units of time | RECCHOICE | Yes | 0 | Yes | Yes | No | No |
PER | Period, in UNITs | DOUBLE | Yes | 0 | Yes | Yes | Yes | No |
DCY | Duty Cycle, percent | DOUBLE | Yes | 0 | Yes | Yes | Yes | No |
For records that use soft device support, OUT can be a constant, a database link or a channel access link, though if it's a constant, no output will be written. See Address Specification, Chapter 1, 2, for information on how to specify database links.
Field | Summary | Type | DCT | Initial | Access | Modify | Rec Proc Monitor | PP |
---|---|---|---|---|---|---|---|---|
OUT | Output Link | OUTLINK | Yes | 0 | No | No | N/A | No |
DTYP | Device Type | DEVCHOICE | Yes | 0 | Yes | No | No | No |
get_graphic_double
and get_control_double
record support routines are called for that field. The PREC field is used when the get_precision
record routine is called. It is used only for the value in the VAL field.See Chapter 2, Fields Common to All Record Types, for more on the record name (NAME) and description (DESC) fields.
Field | Summary | Type | DCT | Initial | Access | Modify | Rec Proc Monitor | PP |
---|---|---|---|---|---|---|---|---|
HOPR | High Operating Range | FLOAT | Yes | 4.3e+9 | Yes | Yes | No | No |
LOPR | Low Operating Range | FLOAT | Yes | 0 | Yes | Yes | No | No |
PREC | Display Precision | SHORT | Yes | 0 | Yes | Yes | No | No |
NAME | Record Name | STRING [29] | Yes | 0 | Yes | No | No | No |
DESC | Description | STRING [29] | Yes | Null | Yes | Yes | No | No |
The Old Period (OPER), Old Duty Cycle (ODCY), and Old Soft Gate Value (OSGV) fields are used to implement monitors for the PER, DCY, and SGV fields, respectively. When the current value doesn't equal the old value, monitors are called for that field.
Field | Summary | Type | DCT | Initial | Access | Modify | Rec Proc Monitor | PP |
---|---|---|---|---|---|---|---|---|
OPER | Old Period, in UNITS | DOUBLE | No | 0 | Yes | No | Yes | Yes |
ODCY | Old Duty Cycle, percent | DOUBLE | No | 0 | Yes | No | Yes | Yes |
OSGV | Old Soft Gate Value | SHORT | No | 0 | Yes | No | No | No |
VAL | Value | SHORT | No | 0 | Yes | Yes | Yes | Yes |
LLOW | Low Logic Level | RECCHOICE | Yes | 0 | Yes | Yes | No | No |
Device support is then checked to see if write_pt is defined.
If device support includes init_record, it is called.
Name | Summary | Description |
---|---|---|
UNIT | Units of time | This field will be used to identify the time units used for time fields. |
OUT | Output Link | This field is used by the device support routines to locate its output. |
PER | Period, in UNITs | Device support must use PER for pulse period. |
DCY | Duty Cycle, percent | Device support must use DCY for the percent of time the signal is high. |
LLOW | Low Logic Level | Device support must use to determine logic low level. |
CEDG | Clock Signal Edge | This field is used by the device support routines to force counting on leading or falling edge of signal. |
GTYP | Gate Type | Device support is responsible for using IGV to determine gating control if GTYP is internal, or SGV if GTYP is external. |
SGV | Soft Gate Value | |
CTYP | Clock Type | If CTYP is external, device support is responsible for using ECR for the clock rate and if CTYP is internal, ECS is the clock source.
|
ECS | External Cocksurely | |
ECR | External Clock Rate, in Hz |
report()This routine is optional. If provided, it prints a report of all device modules.
init()This routine is called once during IOC initialization.
init_record(precord)This routine is optional. If provided, it is called by the record support init_record routine.
get_ioint_info(int cmd,struct dbCommon *precord,IOSCANPVT *ppvt)This routine is called by the ioEventScan system each time the record is added or deleted from an I/O event scan list. cmd has the value (0,1) if the record is being (added to, deleted from) an I/O event list. It must be provided for any device type that can use the ioEvent scanner.
write_pt(precord)This routine issues commands to the output device. It returns the following values:
0: Success.
Other: Error.
Soft Channel
device support module writes the current value of VAL.
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