GE 90-30/20/Micro SVCREQ #26/30: Interrogate I/O

GFK-0467K Chapter 4 Series 90-30/20/Micro Instructions Set 4-163
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.