Change/Read Number Of Words To Checksum; Parameter Block Formats For Svcreq 6 - GE VersaMax PLC User Manual

11.7 Change/Read Number of Words to Checksum

The Service Request Function
For public disclosure
Use SVCREQ 6 to read or change the number of words in the program to be
checksummed. The function is successful unless some number other than 0 or 1 is entered
as the requested operation.

11.7.1 Parameter Block Formats for SVCREQ 6

The parameter block has a length of 2 words.
To read the word count, the first word of the parameter block must contain a zero:
0 (read word count)
address
ignored
address + 1
The function returns the current word count in the second word of the parameter block.
address 0
address + 1 current word count
To change the word count, the first word of the parameter block must contain a one:
1 (change word count)
address
new word count (0 to 32)
address + 1
The PLC will change the number of words to be checksummed to the new value.
GFK-1503E User Manual 203