Rockwell Automation 1771-KA2 Communication Adapter Module - Manual (Page 118)

Start–up and Troubleshooting
Chapter 9
9-16
Sample test rungs are shown in Figure 9.5. The following steps outline
the procedures for programming these rungs for testing. With the
programming terminal connected, follow these procedures:
1. Display the END (of program) statement. The key sequence that
displays this part of the program is as follows:
[SEARCH] [ ]
2. Turn the processor mode select switch to the PROGRAM or PROG
position.
3. Enter the test rungs in the format of Figure 9.5 with the following
addresses:
Rung 1 - Enter the address of an unused input image table bit for the
EXAMINE ON instruction. (Section titled “Test Rungs (Optional)”
describes the reason for selection of this bit.)
Rung 2 - In the LATCH instruction, enter the START bit address for the
command being monitored.
Rung 3 - Enter the address of the DONE bit for the EXAMINE ON
instruction. Enter the address of the START bit for the LATCH
instruction.
Check that the format of these test rungs resembles the one shown in
Figure 9.5.
With these rungs entered, a command can now be initiated. To do this,
use the FORCE ON function of the programming terminal. Perform the
following steps:
4. Turn the processor mode select switch to the TEST position.
5. Position the cursor on the EXAMINE ON instruction of Rung 1.
(On the PLC-2 program panel, display this instruction.)
6. On the programming terminal, press the key sequence for the
FORCE ON function.
With an industrial terminal, press these keys:
[FORCE ON][INSERT]
With program panels, press these keys:
[SELECT][FORCE ON][INSERT]
The START bit is now LATCHED ON. Under normal operation this bit is
being LATCHED and UNLATCHED as the processor executes its scan,
and the command is sent continuously.