Experimental Physics and
Industrial Control System

Mark Rivers <[email protected]> · Tue, 27 Aug 2013 14:46:05 +0000

Hi,

This is the expected behavior.  These are from the comments in drvModbusAsyn.c::readPoller()

        /* See if there are any asynUInt32Digital callbacks registered to be called
         * when data changes.  These callbacks only happen if the value has changed */
...
        /* See if there are any asynInt32 callbacks registered to be called. 
         * These are called even if the data has not changed, because we could be doing
         * ADC averaging */
...
        /* See if there are any asynFloat64 callbacks registered to be called.
         * These are called even if the data has not changed, because we could be doing
         * ADC averaging */
...
        /* See if there are any asynInt32Array callbacks registered to be called.
         * These are only called when data changes */

Mark

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of haquin
Sent: Tuesday, August 27, 2013 8:50 AM
To: tech-talk
Subject: Unexpected Processing Trace (TPRO)

Hi all,

I have a soft IOC running on Linux PC, connected to a modbus TCP server using Asyn (v4.19) ModbusTCP (v2.4) driver, 
EPICS R3.14.2.

in my IOC I run the two following records:
record(longin, tstRB) {
   field(SCAN, "I/O Intr")
   field(DTYP, "asynInt32")
   field(INP, "@asyn($(EQPT):Read_All 2)MODBUS_DATA")
   field(TPRO, "1")
}

record(longin, tstRB2) {
   field(SCAN, "I/O Intr")
   field(DTYP, "asynUInt32Digital")
   field(INP, "@asynMask($(EQPT):Read_All 2 0 0xFFFF )MODBUS_DATA")
   field(TPRO, "1")
}

Both records read the same register in the modbus table which I know is a constant value.

At execution time, I have the following messages for the record tstRB using asynInt32 but no messages related to tstRB2 
using asynUInt32Digital:
cbLow: Process tstRB
cbLow: Process tstRB
cbLow: Process tstRB
cbLow: Process tstRB
cbLow: Process tstRB

If I use asynFloat64 iso asynInt32 I also have the messages,
I expected no messages in all cases since the read value is not changing, I didn't expected the behaviour to be DTYP 
dependent ... Am I wrong ?

Regards

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System