Experimental Physics and
Industrial Control System

I think that is the way the mbboRecord works.  This is from the process() function:

 

        if(prec->nsev < INVALID_ALARM

        && prec->sevr == INVALID_ALARM

        && prec->omsl == menuOmslsupervisory) {

            /* reload value field with B0 - B15 */

            int offset = 1, i;

            unsigned char *bit = &(prec->b0);

            for (i=0; i<NUM_BITS; i++, offset = offset << 1, bit++) {

                if (*bit)

                    prec->val |= offset;

                else

                    prec->val &= ~offset;

            }

        }

        /* convert val to rval */

        convert(prec);

 

If I read this correctly then the first time the record processes sevr==INVALID_ALARM so it will overwrite the VAL field with the Bn fields.

 

Mark