The Allen-Bradley 1764-28BXB base is a part of the Allen-Bradley Bulletin 1764 MicroLogix 1500 base unit series that features embedded I/O and accommodates a processor. It is an essential component in the system assembly of Allen-Bradley MicroLogix 1500 programmable controllers. In addition to the embedded inputs and outputs, the 1764-28BXB base unit houses the power supply and the channel 0 communications port. It also serves as an interface to the expansion I/O as required by a system application. The 1764-28BXB 24 Volt DC Base Unit has 30 Watts of power consumption, 16 Watts of maximum load power, and 400 mA of maximum load current. It comes with 6 relay outputs and 2 isolated relays per unit. It has 8 standard and 8 fast 24 Volts DC inputs. The 1764-28BXB’s high-speed 20 kHz I/O is composed of 8 inputs and 2 outputs. Plus, it has 4 standard FET outputs and 2 fast FET outputs. The FET transistor is only available on this base unit.
The Allen-Bradley 1764-28BXB Base is a required piece of hardware that allows an assembled Allen-Bradley MicroLogix 1500 controller system to supports the maximum number of I/O expansions. It has a width of 168 millimeters (6.62 inches) and a depth of 87 millimeters (3.43 inches). Its height is 138 millimeters (5.43 inches) when the DIN rail latch is open, and its height is 118 millimeters (4.65 inches) when it is closed. The 1764-28BXB is designed to be mounted horizontally on the compact expansion I/O. This unit is compatible with the Allen-Bradley 1764-LRP and 1764-LSP processors. The Allen-Bradley MicroLogix 1500 fault codes can be found in the product manual.