Rockwell Automation 1785-BCM_BEM, D17856.5.4 PLC-5 Backup Communication Module User Manual - Manual (Page 27)

Installing Your PLC-5 Backup System
Chapter 3
3-4
The I/O chassis switch assembly is located on the left side of the chassis
backplane. Table 3.B lists the settings we recommend for the local chassis
of your PLC-5 backup system. (Local refers to the chassis with the PLC-5
processor and the 1785-BCM module.) You can set remote system
switches for your specific application. For more information about setting
your I/O chassis backplane switches refer to the Enhanced and Ethernet
PLC-5 Programmable Controllers User Manual (publication 1785-6.5.12).
Important: The addressing mode and local chassis size you select can
affect the number of remote racks available. Refer to the Enhanced and
Ethernet PLC-5 Programmable Controllers User Manual (publication
1785-6.5.12) for the maximum number of remote racks that can be
addressed by the PLC-5 processor(s) in your system.
Table 3.B
Recommended I/O Chassis Switch Settings for Local Chassis
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 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
Important: * 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.
If your processor is an end device on the Data Highway Plus or remote I/O
link, a terminator must be connected to the processor. In the PLC-5
backup system, you should set each PLC-5 processor in the backup system
as if the other PLC-5 processor does not exist and no 1785-BCM modules
are present. Terminate both links (DH+ and remote I/O):
for a PLC-5/15 or PLC-5/25 processor using switch assembly SW3 on
the PLC-5 processor. See Table 3.C.
for a PLC-5/11, -5/20, -5/30, -5/40, -5/60, or -5/80 processor by
installing an external resistor on the PLC-5 processor. See Table 3.D.
Setting the I/O Chassis
Switches
Terminating the Data Highway
Plus and Remote I/O Links