Experimental Physics and
Industrial Control System

Dirk Zimoch <[email protected]> · Fri, 18 Dec 2009 15:38:35 +0100

Hi all,

I have a quite nasty problem with the mbboDirect record.

When I write a bit pattern directly into the VAL field instead of B0...BF, and

the record has UDF=1, the record writes out the old value instead of the new

one. According to the record reference manual, this is not an illegal operation.

Normally it works. Even if the UDF becomes true during run-time, the worst thing

that happens is that the new value is ignored (which is already bad enough). But

after a reboot the record writes out 0 (and thus switches off all connected

hardware).

The problem is here:

static long process(mbboDirectRecord *prec)
{
...
    if (!prec->pact) {
...
	if(prec->udf) {
	    recGblSetSevr(prec,UDF_ALARM,INVALID_ALARM);
	    goto CONTINUE;
	}
...
	/* convert val to rval */
	convert(prec);
    }

CONTINUE:
...

I am not sure what the purpose of this code is. The record never sets udf true.

Thus only the device support can do so. Thus it cannot make sense the test udf

BEFORE the device support is called.

Best regards,
Dirk

--
Dr. Dirk Zimoch
Paul Scherrer Institut, WBGB/006
5232 Villigen PSI, Switzerland
Phone +41 56 310 5182

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System