The Allen-Bradley 1771-P4S Power Supply Module is a single-slot power supply for PLC-5/1771 I/O backplanes that delivers 5 V DC to the backplane rails at up to 8 A. It accepts 97–132 V AC input at 47–63 Hz and uses a 250 V slow-blow fuse rated at 1.5 A. This module occupies one slot in compatible 1771 universal I/O chassis such as 1771-A1B, -A2B, -A3B, and -A4B, providing reliable backplane power to connected I/O modules. As part of the 1771 power supply family, it powers the I/O backplane but does not perform programming or logic tasks itself.
