1791 Block I/O Repair

Allen Bradley PLC 1791 Block I/O
One Year DO Supply WarrantyOne Year DO Supply Warranty 
'Fast RepairsFast repairs at low costs

We offer extensive repairs for your 1791 Block I/O. We keep many spare parts in stock so that we can repair your 1791 Block I/O as efficiently and effectively as possible. Our standard repair lead time is 2-4 weeks. However, we can often repair your unit much faster if necessary. We can repair most issues with your 1791 Block I/O and if for some reason we cannot repair your unit we will do our best to offer a refurbished unit at the repair cost, so that you can get a working unit back as soon as possible!

Repair Details

We can repair hardware issues and error codes with your 1791 Block I/O such as:

  • Processors
    • Bad communication ports
    • Broken selector/key switches
    • Dead batteries/Bad Battery connections
    • Solid or Blinking RED OK Status Light
    • Solid or Blinking RED RUN Status Light
    • Solid or Blinking RED Fault Status Light
  • I/O Modules 
    • Bad analog inputs or ouptus
    • Bad digital input or outputs
    • Bad relays (stuck on/off)
    • Incorrect voltages on inputs or outputs
    • Incorrect current on inputs or outputs
  • Communication Modules​​​​​​​
    • DF1, DH-485, DH+, Profibus, Remote I/ (RIO) failures and more!
    • Intermittent communication 
    • Solid RED/Blinkging RED communication lights
    • Devicenet, Ethernet, ControlNet, RS232 ports. 
  • Thermocouple Modules/RTD Modules
    • Missing CJC Jumpers
    • Incorrect readings
  • High Speed Counters
    • ​​​​​​​Failed inputs
  • Power Supplies​​​​​​​
    • Dead power supplies
    • Incorrect voltage
  • Chassis/Racks
    • ​​​​​​​Broken Plastic
    • Poor Connections
    • Bad Slots


The 1791 block I/O module series by Allen-Bradley is a series of compact, stand-alone, and remote I/O devices with built-in power supplies, programmable controller interfaces, input/output points, and signal conditioning circuitry for complete system control. These modules are compatible with the Allen-Bradley PLC (2, 3, and 5) controllers and the SLC-500 modular controllers, and they are connected either directly to the controllers in the PLC-3 and PLC-5 programmable controller family or they are connected by using compatible scanner modules. The 1791 block I/O modules have DC power requirements with an operating voltage range between 10 and 30 Volts DC, and they require 200 milliamps of current and a 5.5 Amps (for 10 milliseconds) inrush current to power each block. This series features modules with sinking and sourcing inputs and outputs ranging from 8 to 64 connections, and they have removable remote I/O links, input/output connectors, and terminals for external 24 Volts DC power supply that help reduce wiring costs.

The 1791 block I/O modules have dual DIP switches for setting the I/O configurations and addressing rack numbers. These switches also let the users select and adjust the transmission rates, initiate last racks and I/O groups, and select the last state and DH–485 terminator. A DH-485 port is provided in all modules for connecting to SLC controllers, and this network (DH-485) offers a maximum network communication distance of 4,000 feet. A bi-color LED indicator is also provided on every module for providing power, active, communication, and fuse blown statuses. Depending on the application requirements, multiple I/O blocks can be wired in series via the removable connectors, and a termination resistor must be wired on both ends of the wiring series. The 1791 block I/O modules can provide a maximum network distance range of 2000 to 10,000 cable-feet, and an adjustable baud rate from 57.6 Kilo-baud to 230.4 Kilo-baud.

Part Number Description Price Action
1791-0A161791 Block I/O Repair Service$186.00cartAdd To Cart
1791-0A321791 Block I/O Repair Service$770.40cartAdd To Cart
1791-0B161791 Block I/O Repair Service$186.34cartAdd To Cart
1791-0B321791 Block I/O Repair Service$175.76cartAdd To Cart
1791-16A01791 Block I/O Repair Service$382.11cartAdd To Cart
1791-16AC1791 Block I/O Repair Service$671.66cartAdd To Cart
1791-16B01791 Block I/O Repair Service$185.90cartAdd To Cart
1791-16BC1791 Block I/O Repair Service$379.03cartAdd To Cart
1791-24A81791 Block I/O Repair Service$873.93cartAdd To Cart
1791-24AR1791 Block I/O Repair Service$978.08cartAdd To Cart
1791-24B81791 Block I/O Repair Service$282.24cartAdd To Cart
1791-24BR1791 Block I/O Repair Service$281.32cartAdd To Cart
1791-32A01791 Block I/O Repair Service$284.15cartAdd To Cart
1791-32B01791 Block I/O Repair Service$341.86cartAdd To Cart
1791-8AC1791 Block I/O Repair Service$446.58cartAdd To Cart
1791-8AR1791 Block I/O Repair Service$679.90cartAdd To Cart
1791-8BC1791 Block I/O Repair Service$147.15cartAdd To Cart
1791-8BR1791 Block I/O Repair Service$682.88cartAdd To Cart
1791-IOBB1791 Block I/O Repair Service$230.41cartAdd To Cart
1791-IOBW1791 Block I/O Repair Service$381.19cartAdd To Cart
1791-IOBX1791 Block I/O Repair Service$633.10cartAdd To Cart
1791-IOVW1791 Block I/O Repair Service$345.30cartAdd To Cart
1791-IOVX1791 Block I/O Repair Service$544.81cartAdd To Cart
1791-N4C21791 Block I/O Repair Service$378.57cartAdd To Cart
1791-N4V21791 Block I/O Repair Service$483.77cartAdd To Cart
1791-NDC1791 Block I/O Repair Service$742.63cartAdd To Cart
1791-NDV1791 Block I/O Repair Service$281.62cartAdd To Cart
1791-OA161791 Block I/O Repair ServiceAskRequest A Quote
1791-OA321791 Block I/O Repair ServiceAskRequest A Quote
1791-OB161791 Block I/O Repair ServiceAskRequest A Quote
1791-OB321791 Block I/O Repair Service$187.61cartAdd To Cart
Part Number Description Price Action
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