Rockwell Automation 1771-KA2 Communication Adapter Module - Manual (Page 109)

Start–up and Troubleshooting
Chapter 9
9-7
FORCE ON Function
The FORCE ON function, available with each of the 3 programming
terminals, can be a useful troubleshooting tool. When used in conjunction
with the optional test rungs of section titled “Test Rungs (Optional),” this
function controls the initiation of each command programmed at a station.
An advantage of this programming terminal function is that it can be used
only when the programming terminal is connected to the processor, or, in
this case, to the PROGRAM INTERFACE socket of the communication
adapter module. When the programming terminal is disconnected, the
FORCE function is removed.
A FORCE function can be entered in either the TEST or RUN mode. On
the industrial terminal and the PLC program panel, the cursor must point
to the instruction for a FORCE function to be entered. On the PLC-2
program panel, an instruction must be displayed for a FORCE function to
be entered.
On the industrial terminal, use the following key sequence for the FORCE
ON function:
To initiate [FORCE ON][INSERT]
To remove [FORCE ON][REMOVE]
REMOTE/LOCAL FAULT Bits
The REMOTE and LOCAL FAULT bits provide the chief indicator of a
hardware- related fault that prevents normal communication. As
recommended in chapter 7, these bits must be programmed to control
some output device to alert plant personnel of a fault condition. When
this output device signals a fault condition, a programming terminal can
then be used to display the ON/OFF status of any REMOTE or LOCAL
FAULT bit station processor.
Figure 9.3 summarizes the significance of both REMOTE FAULT bits.