Allen-Bradley 1791-8AR Discrete Block I/O module

The Allen-Bradley 1791-8AR is a Discrete Block I/O module that is manufactured by Allen-Bradley. This product belongs to the legacy Block I/O modules, designed to provide compact Remote I/O (RIO) solution. Block I/O modules, including the 1791-8AC has embedded power supply, RIO interface and I/O terminals, enabling the module to act as a complete RIO node for implementing Didtributed I/O architecture.

The 1791-8AR is compatible for use with Allen-Bradley legacy PLC2, PL3, PLC5 processors as well as SLC500 controllers that is installed with the SLC 500 that is installed with Remote I/O scanner module with catalog number 1747-SN. It supports Allen-Bradley’s RIO protocol, a high-speed and long distance distributed I/O protocol that follows Daisy-chain topology, supporting 57.6K, 115.2K and 230.4K baud rates. Cable to Baud rate relationship are 10,000 cable-feet for 57.6k; 5000 cable-feet for 115.2K and 2500 cable-feet for 230.4 K. Each end of the RIO nodes require installation of terminating resistors with value 82 Ohms or 150 Ohms.

Technical specifications for 1791-8AR

ManufacturerRockwell Automation

Output Voltage Range125 VDC at 1 A Resistive Maximum; 20 - 30 VDC at 1 A Resistive Maximum; 125 VD at 0.2A resistive maximum

BrandAllen-Bradley

Product Type:Block I/O

No. of Inputs:Eight (8)

No. of Groups:1 group of 8

On-state Voltage range:79-132VAC

No of outputs:Eight (8

Output Type:Relay

External Power, Voltage:85-132VAC

External Power, Current:150 mA

Mounting:Vertical / Horizontal

Power Dissipation, maximum:12.9 Watts

Thermal Dissipation, maximum:56.1 BTU/Hr

Part Number/Catalog No.1791-8AR

Voltage120V ac

Inputs per Block8

Input On-state Voltage Range79-132V ac

Input On-state Current12.3mA @ 132V max.

Input Off-state Voltage35V max.

Input Off-state Current2.3mA min.

Outputs per Block8

External Power85-132V ac

Dimensions6.95 x 2.7 x 3.85 in.

Product Lifecycle Status*Discontinued/Obsolete