Rockwell Automation 1785-BCM_BEM, D17856.5.4 PLC-5 Backup Communication Module User Manual User Manual
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Reference Information
Appendix B
B-2
Q.
In which slot of the local I/O chassis do I install the 1785-BEM
module?
A.
We recommend that you install the 1785-BEM module in the
right-most slot of the first I/O module group in the I/O chassis for ease
in making connections and programming. Note that the 1785-BEM
module must be in the same I/O group as the 1785-BCM module.
(Refer to Chapter 3 and Chapter 4 for more information.)
Q.
Does the 1785-BEM module have to go next to the 1785-BCM
module?
A.
Yes. They should be placed in the same I/O module group.
Q.
How do I set the local I/O chassis backplane switches for a PLC-5
backup system?
A.
Set the switches as shown in the following table. (Refer to Chapter 3
for more information.)
Set switch(es)
To this position:
1
OFF – to turn off outputs in the chassis when a fault is detected.
2 and 3
both OFF – these switches are not used
4 and 5
1
4 – ON
configure for 1/2-slot addressing*
5 – OFF
configure for 1/2-slot addressing*
6 and 7
as required for your application
8
as required for your application
*
The 1785-BCM module appears to the PLC-5 processor as a 32-point input module. You must
configure switches 4 and 5 for 1/2-slot addressing or 1-slot addressing. If not configured as 1/2-
or 1-slot addressing, a PLC-5 processor fault will occur. If you are installing a 1785-BEM
module, you must select 1/2-slot addressing.
Q.
How do I set the remote I/O chassis backplane switches for a
PLC-5 backup system?
A.
The operation of the PLC-5 backup system is independent of the
operation of the remote I/O chassis; therefore, you can set these
switches as required for your application. For more information about
setting the I/O chassis switches, refer to the PLC-5 Enhanced and
Ethernet Programmable Controllers User Manual (publication
1785-6.5.12).