GE PACSystems RX7i - Page 300

Chapter 6. Service Request Function
GFK-2950C February 2018 285
SVC_REQ 6 Example
When enabling contact
#FST_SCN is set, the
parameter blocks for the
checksum task function are
built. Later in the program,
when input %I00137
transitions on, the number of
words being check-summed
is read from the CPU
operating system. This
number is increased by 16,
with the results of the
ADD_UINT function being
placed in the hold new count
for set parameter. The
second service request block
requests the CPU to set the
new word count.
The example parameter blocks are located at address %L00150. They have the following contents:
%L00150
0 = read current count
%L00151
hold current count
%L00152
1 = set current count
%L00153
hold new count for set