Troubleshooting
Chapter 7
77
You can verify cable connections and operation of your installed ASCII
module on your industrial terminal as follows.
1. Turn off power to I/O chassis. Place your module in module group
1, slot 1. Turn on power.
2. Load a brief program into processor memory. Use the program
(Figure 6.2 for PLC-2 family controllers, Figure 6.3 for PLC-3
controllers) if your processor memory is empty. If you have loaded
your “Getting Started Program”, insert only rungs 3 and 4 following
rung 2 of the “Getting Started Program”. Add a temporary end
instruction (PLC-2 family), or an end rung (PLC-3 controller).
3. Set your industrial terminal to alphanumeric mode and select a
communication rate of 300 baud. Do this by entering the following
key sequence using the alphanumeric keytop overlay.
Press [MODE SELECT]1213[RETURN]
The cursor appears at the upper left corner of a blank screen.
The module’s CHANNEL ACTIVE LED illuminates when the industrial
terminal is in alphanumeric mode and the module has power.
4. Place the processor in run/program mode (PLC-2 family controller)
or in run monitor (PLC-3 controllers).
5. Enter characters on the keyboard.
Results Characters should be displayed as you enter them.
If not, check the following:
The module’s internal programming plugs are set correctly (chapter 3,
Figure 3.8).
Cables to the I/O chassis are connected correctly.
PLC-3 controller LIST functions are entered correctly, and/or adapter
module switch is set correctly. (Does the proper channel number LED
indicator illuminate on the 1775-S4A I/O scanner, and does the
ACTIVE LED indicator illuminate on the 1771-AS remote I/O adapter
module?)
Testing the ASCII Module and
Cables
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