Rockwell Automation 1771-KA2 Communication Adapter Module - Manual (Page 21)

Station Hardware
Chapter 2
2-11
Figure 2.7
1771-P1 System Power Supply
ALLEN-BRADLEY
DC ON
Battery
Low
10865-I
When using the PLC-2/20 or PLC-2/30 processor, any of these supplies
can power the I/O chassis so long as core memory is not being used.
(Refer to processor manuals.) An auxiliary power supply (cat. no.
1771-P2) closely resembles the system power supply shown in Figure 2.7.
PLC-2 power supply module (cat. no. 1772-P1) is not a separate unit, but
is enclosed within the metal chassis of the PLC-2/20 or PLC-2/30
processor.
PLC-2 power supplies must be series B or later for communication
adapter module compatibility. On both of these supplies, a label on the
front edge of the circuit board identifies the series level. To locate this
label, remove AC power from the supply and remove the metal front plate
that covers the module. If the label shows the catalog number but not the
series level, the module is series A. Otherwise, series B or later is
indicated.