RE: Understanding Motor Record

[Mark L Rivers via Tech-talk <tech-talk at aps.anl.gov>]

Hi Heinz,

If you set UEIP=0 does it work OK?

Did you look for where in the motor record it is testing UEIP without also testing the encoder present bit in MSTA?  Has that logic changed?

Mark


-----Original Message-----
From: Heinz Junkes <junkes at fhi-berlin.mpg.de> 
Sent: Tuesday, November 16, 2021 2:17 PM
To: Torsten Bögershausen <torsten.bogershausen at ess.eu>
Cc: Mark L Rivers <rivers at cars.uchicago.edu>; EPICS Tech Talk <tech-talk at aps.anl.gov>
Subject: Re: Understanding Motor Record

Hello Torsten and Mark,

thank you for your prompt replies.

In fact I had problems with two motors where UEIP was set to 1(Yes). Has always been like this ;-)

According to the documentation, this should also work if MSTA indicates that no encoder is present.:

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. 
The state of the UEIP, together with the MSTA encoder indicator, determine:

	• if the RRBV is set to either the feedback (REP) or the command (RMP) position.
	• whether absolute or relative position commands are used.


epics@felgate:~$ caget FHIFEL:M12PH.MSTA
FHIFEL:M12PH.MSTA              3

	• DIRECTION: last raw direction; (0:Negative, 1:Positive)
	• DONE: motion is complete.
	• PLUS_LS: plus limit switch has been hit.
	• HOMELS: state of the home limit switch.
	• Unused
	• POSITION: closed-loop position control is enabled.
	• SLIP_STALL: Slip/Stall detected (eg. fatal following error)
	• HOME: if at home position.
	• PRESENT: encoder is present.
	• PROBLEM: driver stopped polling, or hardware problem
	• MOVING: non-zero velocity present.
	• GAIN_SUPPORT: motor supports closed-loop position control.
	• COMM_ERR: Controller communication error.
	• MINUS_LS: minus limit switch has been hit.
	• HOMED: the motor has been homed.

This now seems to be behaving differently.

Danke,
Heinz

> On 16. Nov 2021, at 18:15, Torsten Bögershausen <torsten.bogershausen at ess.eu> wrote:
> 
> Hej Mark and Heinz,
> 
> If I command the motor to -10 mm,
> and it runs into the limit switch at -2.970
> 
> The we see that .VAL stays at -10 mm, (where the motor should have gone)
> and .RBV is -2.970 (where the motor is)
> 
> So the “correlation” is lost - on purpose.
> Thats my understanding.
> 
> HTH
> /Torsten
> 
> 
> 
>> On 16 Nov 2021, at 18:09, Mark L Rivers via Tech-talk <tech-talk at aps.anl.gov> wrote:
>> 
>> Hi Heinz,
>> 
>> It looks like you are using an encoder (UEIP=Yes), and your encoder readback (REP) is 0.  When the motor record hits a limit switch I believe it sets the DVAL to the readback value.
>> 
>> Mark
>> 
>> 
>> From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Heinz Junkes via Tech-talk <tech-talk at aps.anl.gov>
>> Sent: Tuesday, November 16, 2021 10:59 AM
>> To: EPICS Tech Talk <tech-talk at aps.anl.gov>
>> Subject: Understanding Motor Record
>> 
>> I am having problems with Motor-Record right now.
>> I am using Epics 7 and the latest MotorRecord
>> (master: https://github.com/epics-modules/motor)
>> 
>> When I reach a Limit - Switch, then there is no
>> correlation between RMP and DVAL/VAL anymore?
>> 
>> RMP : 1361 vs. DVAL: 0 and VAL : 0 ??
>> 
>> I'm using the same hardware as I have for 10 years (Oms MAXv), only 
>> now I have Epics7 with the new motor-record in use.
>> 
>> I also have the feeling that something with the conversion of the
>> EGU and the direction etc. does not fit.
>> But unfortunately can not specify yet because "somehow some is wrong”
>> 
>> Danke Heinz
>> 
>>> dbpr FHIFEL:M11PH,10
>> ACCL: 1             ACKS: NO_ALARM      ACKT: YES           ADEL: 0
>> ALST: 0             ASG :               ASP : PTR 0x0       ATHM: 0
>> BACC: 1             BDST: 0             BKLNK: ELL 0 [0x0 .. 0x0]
>> BKPT: 00            BVEL: 4.5           CARD: 0             CBAK: PTR 0x15f9bf8
>> CDIR: 1             CNEN: Disable       DCOF: 0
>> DESC: M1 Pinhole OMS_Z                  DHLM: 140           DIFF: 0
>> DINP: CONSTANT      DIR : Pos           DISA: 0             DISP: 0
>> DISS: NO_ALARM      DISV: 1             DLLM: -140          DLY : 0
>> DMOV: 1             DOL : CONSTANT      DPVT: PTR 0x15f9c18 DRBV: 0
>> DSET: PTR 0x462d34  DTYP: OMS MAXv      DVAL: 0             EGU : mm
>> ERES: 1.171875e-04  EVNT:               FLNK: CONSTANT      FOF : 0
>> FOFF: Frozen        FRAC: 1             HHSV: NO_ALARM      HIGH: 0
>> HIHI: 0             HLM : 140           HLS : 1             HLSV: NO_ALARM
>> HOMF: 0             HOMR: 0             HOPR: 0             HSV : NO_ALARM
>> HVEL: 4.5           ICOF: 0             IGSET: 0            INIT:
>> JAR : 7.5           JOGF: 0             JOGR: 0             JVEL: 4.5
>> LCNT: 0             LDVL: 0             LLM : -140          LLS : 0
>> LLSV: NO_ALARM      LOCK: NO            LOLO: 0             LOPR: 0
>> LOW : 0             LRLV: 0             LRVL: 0             LSET: PTR 0x1548258
>> LSPG: Go            LSV : NO_ALARM      LVAL: 0             LVIO: 0
>> MDEL: 0             MIP : 0             MISS: 1
>> MLIS: ELL 148 [0x2190a58 .. 0x177254c8] MLOK: 01 54 f4 10   MLST: 0
>> MMAP: 0             MOVN: 0             MRES: 1.171875e-04  MSTA: 7
>> NAME: FHIFEL:M11PH  NMAP: 0             NSEV: NO_ALARM      NSTA: NO_ALARM
>> NTM : YES           NTMF: 2             OFF : 0             OMSL: supervisory
>> OUT : VME_IO #C0 S2 @                   PACT: 0             PCOF: 0
>> PHAS: 0             PINI: NO            POST:               PP  : 0
>> PPN : PTR 0x0       PPNR: PTR 0x0       PREC: 3             PREM:
>> PRIO: LOW           PROC: 0             PUTF: 0             RBV : 0
>> RCNT: 0             RDBD: 0.1           RDBL: CONSTANT      RDES: PTR 0xcbd400
>> RDIF: 0             REP : 0             RHLS: 1             RINP: CONSTANT
>> RLLS: 0             RLNK: CONSTANT      RLV : 0             RMOD: Default
>> RMP : 1361          RPRO: 0             RRBV: 0             RRES: 999.99
>> RSET: PTR 0x462f4c  RSTM: NearZero      RTRY: 5             RVAL: 0
>> RVEL: 0             S   : 5             SBAK: 3             SBAS: 3
>> SCAN: Passive       SDIS: CONSTANT      SET : Use           SEVR: NO_ALARM
>> SMAX: 12            SPDB: 0             SPMG: Go            SPVT: PTR 0x0
>> SREV: 12800         SSET: 0             STAT: NO_ALARM      STOO: CONSTANT
>> STOP: 0             STUP: OFF           SUSE: 0             SYNC: 0
>> TDIR: 1             TIME: 2021-11-16 16:45:24.834573822     TPRO: 0
>> TSE : 0             TSEL: CONSTANT      TWF : 0             TWR : 0
>> TWV : 1             UDF : 0             UDFS: INVALID       UEIP: Yes
>> UREV: 1.5           URIP: No            VAL : 0             VBAS: 4.5
>> VELO: 7.5           VERS: 7.2           VMAX: 18            VOF : 0
>