Re: Understanding Motor Record

[Heinz Junkes via Tech-talk <tech-talk at aps.anl.gov>]

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
>

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