Allen-Bradley 1791-8BC Combination discrete I/O module

The 1791-8BC is a Combination discrete input and output module from the Block I/O series of Allen-Bradley. This module is ideally used to implement distributed I/O architecture as it comes with a rackless design and supports DIN rail mounting. This module is compatible for use with Allen-Bradley’s PLC-2, PLC-3, 1785 PLC-5 series, 1747 SLC 500 Series, Logix automation platforms such as CompactLogix and ControlLogix controllers via a Remote I/O (RIO) communication module. The 1791-8BC communicates with partner controllers via Remote IO (RIO) communication protocol via 1771-CD or Belden 9463 3-wire communication cable at transmission rates of 57.6K and 115.2K baud and 230.4K baud. This RIO communication capability is available via terminals 6 (BLU), 7 (SHD), and 8 (CLR). The RIO network's first and last node must be terminated with a terminating resistor with values 150 Ohms at 57.6K and 115.2K baud rates and 82 Ohms at 230.4K baud. This terminating resistor is connected across 6 (BLU) and 8 (CLR) terminals. This module has Eight (8) 24 VDC discrete inputs arranged in a single group. An input voltage range of 10-30 VDC can be applied to the input terminals along with a minimum On-state current of 2.5 mA at 10 VDC and a maximum input current of 11.0 mA at 30 VDC.

Technical specifications for 1791-8BC

ManufacturerRockwell Automation

BrandAllen-Bradley

Part Number/Catalog No.1791-8BC

ManufacturerRockwell Automation

Voltage24V dc

SeriesBlock I/O

Inputs per Block8

Part Number1791-8BC

Input On-state Voltage Range10-30V dc

Product DescriptionCombination Discrete Input and Output Module

Input On-state Current11mA @ 30V max.

No. of I/O channelsSixteen (16)

Input Off-state Voltage5V dc max.

No. of input channelsEight (8)

Input Off-state Current1.5mA min.

Input signal, nominal24 VDC

Outputs per Block8

Input signal, range10-30 VDC

Output Voltage Range10-30V dc

On state current11.0mA @ 30V, max; 2.5mA @ 10V, min.

External Power19.2-30V dc

Off-state current1.5mA

DimensionsInches: 6.95H X 2.7W X 3.85D Millimeters: 176.5H X 68.8W X 98D

No. of Output channelsEight (8)

UPC10612598127082

Output voltage10-30 VDC

Product Lifecycle Status*Discontinued/Obsolete

Output currentVertical mounting: 500mA @ 60oC, 1A @ 30oC Horizontal mounting: 250mA @ 60oC, 500mA @ 30oC

External Power supply19.2–30V dc

Current Draw300 mA, maximum

LED indicatorsIndividual channel LED indicators; OK LED;