GFK-0467K Chapter 4 Series 90-30/20/Micro Instructions Set 4-153
4
SVCREQ #12: Read PLC Run State
Use SVCREQ function #12 to read the current RUN state of the PLC CPU.
Note
Of the CPUs discussed in this manual, Service Request 12 is supported only
by 90-30 CPUs, beginning with Release 8.0.
The parameter block is an output parameter block only; it has a length of one word.
1 = run/disabled address
2 = run/enabled
Example:
In the following example, the PLC run state is always read into location %R4002. If the state is
Run/Disabled, the CALL function calls program block DISPLAY.
| _____ _____
|%I0102 | | | |
|——| |———| SVC_|——————————| EQ_ |—
| | REQ | | WORD| __________
| | | | | | |
| CONST —|FNC | CONST —|I1 Q|————————| DISPLAY |—
| 0012 | | 0001 | | |__________|
| | | | |
| %R4002—|PARM | %R4002—|I2 |
| |_____| |_____|
|