4

SVCREQ #26/30: Interrogate I/O

Use SVCREQ function #26 (or #30—they are identical; i.e., you can use either number to accomplish the same thing) to interrogate the actual modules present and compare them with the rack/slot configuration, generating addition, loss, and mismatch alarms, as if a store configuration had been performed. This SVCREQ will generate faults on both the PLC and I/O fault tables, depending on the fault.

This function has no parameter block and always outputs power flow.

Note

The time for this SVCREQ to execute depends on how many faults exist. Therefore, execution time of this SVCREQ will be greater for situations where more modules are at fault.

Example:

In the following example, when input %I0251 is ON, the actual modules are interrogated and compared to the rack/slot configuration. Output %Q0001 is turned on after the SVCREQ is complete.

 

_____

 

%I0251

%Q0001

—— ———

SVC_——————————————————————————————————————————————————————————( )—

 

REQ

 

 

CONST —FNC

 

+0026

 

 

%R0050 —PARM

 

_____

 

 

 

 

Note

This Service Request is not available on Micro PLCs.

GFK-0467K

Chapter 4 Series 90-30/20/Micro Instructions Set

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Image 244
GE 90-30/20/Micro manual Svcreq #26/30 Interrogate I/O