The 1794-ASB is an Allen-Bradley Remote I/O communication Adapter module. This product belongs to the Flex I/O product family of distributed I/O modules.

The 1794-ASB has One (1) Remote I/O interface. This RIO protocol is a legacy protocol, utilizing Belden 9463 or equivalent cables for connecting the device to the RIO scanner. This module is compatible for use with Allen-Bradley Legacy controllers such as PLC2, PLC3 and PLC5 controllers as well as SLC500 automation platforms. It may also be used modern Logix controller platforms as well as with 3rd party devices and encompass partner modules.

The 1794-ASB sends and receives data to and from the controller, via Block Transfer Read (BTR) and Block Transfer Write (BTW) instructions. Using these instructions, packets of data may be sent simultaneously or sequentially, depending of the required speed.

The 1794-ASB supports communication rate of 57.6Kbps, 115.2Kbps, and 230.4kbps. The module’s intended supply voltage range is 11VDC-31.2VDC, including 5% ac ripple while the nominal supply is 24VDC. It supports installation of up to Eight (8) Flex I/O modules, for successful implementation of distributed I/O architecture. This module has built-in status indicator such as Power LED, Adapter Active LED, Adapter Fault LED and Local Fault LED. This module is mounted to a standard DIN rail and has an open type enclosure which means the 1794-ASB requires installation inside an appropriate enclosure that protects the device from industrial element and contaminants.

Depending on the controller used, the 1794-ASB may be configured using RSLogix 5, RSLogix 500, RSLogix 5000 and Studio 5000 Design environment.

The maximum consumption of power is 450 mA from a constant 24 Volts DC power input. The maximum power dissipation is 4.6 Watts at 31.2 Volts DC and the thermal dissipation is 15.7 BTU/hour at 31.2 Volts DC.

The 1794-ASB’s dimensions are approximately 4x 2x 4 inches and weigh only 6 ounces. The Allen-Bradley 1794-ASB is an obsolete Adapter Module and is part of the FLEX I/O series. It connects FLEX I/O modules to I/O scanner ports via a communication network. It has a built-in power supply which converts 24VDC to 5 VDC for the backplane in order to power the FLEX I/O modules. It also functions with the Allen Bradley PLC 3 and 5 series. Additionally, the 1794-ASB can recognize the safe state data for the FLEX Integral analog modules, and it is capable of using thirty-two point FLEX I/O units. The user must use a 1794-ASB Series D or later module when utilizing the FLEX Integral analog modules in the configuration of your setup. This unit can communicate with the 1747-SN via Remote I/O communications and RSLogix 500 software.