Installation manual

Publication 1747-RM001G-EN-P - November 2008
B-56 SLC Status File
S:49 Dynamic Config Discrete Input Interrupt - Compare Value
You enter a bit mapped value that corresponds to the bit
transitions that must occur in the discrete I/O card for a
count or interrupt to occur. Only bits 0 to 7 are used in the
DII function. Setting a bit indicates that the bit must
transition from a 0 to a 1 to satisfy the compare condition
for that bit. Clearing a bit indicates that the bit must
transition from a 1 to a 0 in order to satisfy the compare
condition for that bit. An interrupt or count will be generated
upon the last bit transition of the compare value. This value
is applied upon detection of a DII Reconfigure bit, each DII
ISR exit, and each end of scan (END, TND, or REF).
To provide protection from inadvertent data monitor
alteration of your selection, program an unconditional MOV
instruction containing the compare value of your DII to S:49.
•••
S:50 Dynamic Config Discrete Input Interrupt - Preset
When this value is equal to 0 or 1, an interrupt is generated
each time the comparison specified in words S:48 and S:49
is satisfied. When this value is between 2 and 32767, a
count will occur each time the bit comparison is satisfied.
An interrupt will be generated when the accumulator value
reaches 1 or exceeds the preset value. This value is applied
on detection of DII Reconfigure bit, each DII ISR exit, and at
each end of scan (END, TND, or REF).
To provide protection from inadvertent data monitor
alteration of your selection, program an unconditional MOV
instruction containing the preset value of your DII to S:50.
•••
S:51 Status Discrete Input Interrupt - Return Mask
The return mask is updated immediately preceding entry
into the DII subroutine. This value contains the bit map of
the bit transitions that caused the interrupt. The bit is set if
it was included in the list of bit transitions that caused the
interrupt, (specified to transition in the S:48 and S:49
comparisons). The bit is cleared if it was masked. This value
is cleared by the processor upon exit of the DII subroutine.
Use this value to validate the interrupt transitions. Or when
dynamically reconfiguring (sequencing) the DII, you can use
this value inside your DII’s subroutine to help determine or
validate its position in the sequence.
•••
S:52 Status Discrete Input Interrupt - Accumulator
The DII accumulator contains the number of counts that
have occurred (see S:50.) When a count occurs, and the
accumulator is greater than or equal to the preset value, a
DII interrupt is generated.
•••
Table B.4 Status File Functions (Continued)
Address Classification Description Fixed
5/01
5/02 5/03 5/04 5/05