Error "drvModbusAsyn::readPoller ... invalud memory request 3, max=3" of module Eurotherm2k

[LiangChih Chiang via Tech-talk <tech-talk at aps.anl.gov>]

Hello, EPICS mates,

I use module Eurotherm2k (https://github.com/jwlodek/eurotherm2k)

to access controller Eurothermm 3508.

It's ok mostly, but I can't set the P/I/D values.

And there are two errors showed repeatedly:

2024/11/07 09:07:35.155 drvModbusAsyn::readPoller port Eurotherm_E3K01_1_1_Rd_PID invalid memory request 3, max=3
2024/11/07 09:07:35.852 drvModbusAsyn::readPoller port Eurotherm_E3K01_1_1_Rd_PV invalid memory request 4, max=3

In " E3K01_1_1"

"E3K01" is the port name,

the following "1" is the Modbus address,

then "1" is the loop number.

I found that in the file eurothermModbus.c of the module, it calls drvMosbusAsynConfigure:

        /* Create modbus channels for the PV, target setpoint and manual output */
        mkname(str, strmaxlen, asynPortName, modbusAddress, loopNumber, 0, "PV");
        asynRet = drvModbusAsynConfigure(str, asynPortName, modbusAddress,
                                MODBUS_READW, loopStart+PV_OFFSET, 3+2,
                                0, EUROTHERM_POLL_MS, "");
        if (asynRet != asynSuccess) {
                LOG_ERROR("drvModbusAsynConfigure failed with error %d", asynRet);
                free(str);
                return -EIO;
        }

        /* Create modbus channels for the PID parameters */
        mkname(str, strmaxlen, asynPortName, modbusAddress, loopNumber, 0, "PID");
        asynRet = drvModbusAsynConfigure(str, asynPortName, modbusAddress,
                                MODBUS_READW, loopStart+PID_OFFSET, 3+1,
                                0, EUROTHERM_POLL_MS, "");
        if (asynRet != asynSuccess) {
                LOG_ERROR("drvModbusAsynConfigure failed with error %d", asynRet);
                free(str);
                return -EIO;
        }

And in the file eurothermModbusLoop.template, the records uses the ports created above:

# PV: address 1
# % gdatag,pv,ro,$(gda_name=),PVRBV
# % archiver 1 Monitor
record(ai, "$(P)$(Q):PV:RBV") {
  field(DESC, "Temperature Readback")
  field(DTYP, "asynInt32")
  field(INP, "@asyn(Eurotherm_$(PORT)_$(ADDR)_$(LOOP=1)_Rd_PV,0,1000)MODBUS_DATA")
  field(EGU, "$(EGUT=C)")
  field(SCAN, "I/O Intr")
}

# % gdatag,pv,ro,$(gda_name=),SPRBV
# % archiver 10 Monitor
record(ai, "$(P)$(Q):SP:RBV") {
  field(DESC, "Setpoint Readback")
  field(DTYP, "asynInt32")
  field(INP, "@asyn(Eurotherm_$(PORT)_$(ADDR)_$(LOOP=1)_Rd_PV,1,1000)MODBUS_DATA")
  field(EGU, "$(EGUT=C)")
  field(SCAN, "I/O Intr")
  field(ASLO, "0.1")  
}

# % gdatag,pv,ro,$(gda_name=),ORBV
# % archiver 1 Monitor
record(ai, "$(P)$(Q):O:RBV") {
  field(DESC, "Output Readback")
  field(DTYP, "asynInt32")
  field(INP, "@asyn(Eurotherm_$(PORT)_$(ADDR)_$(LOOP=1)_Rd_PV,2,1000)MODBUS_DATA")
  field(EGU, "%")
  field(SCAN, "I/O Intr")
  field(ASLO, "0.1")
  field(PREC, "1")
}

Would you please provide some suggestions?