The PLC-5-60 (1785-L60B) standard processor by Allen-Bradley is a 64K word programmable controller in the PLC-5 Enhanced Programmable Controller family installed on the left-most slot of the 1771 I/O chassis, which controls the inputs and outputs of field devices and it has a maximum I/O capacity of 3072 (with 16 input/output bit = 1 word). The controller draws a backplane current of 3.3A at 5V DC from the I/O chassis power supply and provides circuit voltage isolation between the communication ports tested at 500V for 60 seconds and between the communication port and relay cartridge, also tested at 1000V for 60 seconds. The controller is compatible with most 1771, 1794 I/O, 1746 I/O, and 1791 eight, sixteen, thirty-two-point, and intelligent I/O modules. The 1785-L60B supports the use of a relay cartridge (1785-RC), which provides an interface with external devices, and the controller itself can support a maximum of 24 I/O racks, with itself occupying Rack 0.

The PLC-5-60 has 3 different I/O hardware-addressing modes (2-slot, 1-slot, and ½-slot addressing) with the 2-slot mode addressing any mix of 8-point modules, a pair of 16-point modules, and no 32-point module addressing, the 1-slot addressing any mix of 8 or 16-point module, and a pair of 32-point modules, and the ½-slot mode addressing any mix of 8, 16, and 32-point modules. The processor module has a maximum of I/O chassis connection of 93 (32 per link) and it communicates via the 25-pin D-shell serial port, which supports standard RS-232 and RS-423 serial interface, a DH+ port for connection to the DH+ network and a remote I/O port (Channel 1B port). The PLC-5-60 has an operational temperature range between 0 and 60 ^oC (32 and 140 ^oF) around a relative humidity range of 5-95% without condensation, and it is built for an operational shock of 30G and a vibration of 2G at 10-500Hz. It weighs approximately 1.42kg (3lb) and comes in an open-style enclosure, and it is UL, C-TICK, CE, and CSA-certified. The PLC-5-60 has 3 different I/O hardware-addressing modes (2-slot, 1-slot, and ½-slot addressing) with the 2-slot mode addressing any mix of 8-point modules, a pair of 16-point modules, and no 32-point module addressing, the 1-slot addressing any mix of 8 or 16-point module, and a pair of 32-point modules, and the ½-slot mode addressing any mix of 8, 16, and 32-point modules. The processor module has a maximum of I/O chassis connection of 93 (32 per link) and it communicates via the 25-pin D-shell serial port, which supports standard RS-232 and RS-423 serial interface, a DH+ port for connection to the DH+ network and a remote I/O port (Channel 1B port). The PLC-5-60 has an operational temperature range between 0 and 60 ^oC (32 and 140 ^oF) around a relative humidity range of 5-95% without condensation, and it is built for an operational shock of 30G and a vibration of 2G at 10-500Hz. The PLC-5-60 weighs approximately 1.42kg (3lb) and comes in an open-style enclosure, and it is UL, C-TICK, CE, and CSA-certified.