Rockwell Automation 9323-S5500D A.I. SERIES MICROLOGIX 1000 AND PLC-500 SOFTW - Manual (Page 452)

Troubleshooting and Diagnostics
19-21
The following screen demonstrates the effect of forced I/O:
On the first rung, the input address is forced on, causing the input bit in the data table
to turn on, thus causing the output for that rung to be true. Both instruction indicators
appear in reverse video.
On the second rung, although the output is forced ON, the instruction does not appear
in reverse video because the force is written directly to the output device, not to the data
table. The rung is not true so the output data table value is not on.
On the third rung, although SECOND_OUTPUT is forced ON, the data table value is
still OFF. Therefore, the output for the third rung (THIRD_OUTPUT) is not energized.
Entering Forces
You can program forces in several ways:
•
Position the cursor on an instruction in the ladder program which references a real
I/O address and press [F7] Force , then [F1] oFf , [F2] On , or [F3] Remove . (See
Force Current Bit below.)
•
Edit the force table for inputs or outputs using a display similar to the monitor data
file screen. Forces may be enabled, disabled or removed. (See Force Table
Monitor on page 19-26 .)
ƒ
•
‚
•
‚
ƒ