Product Overview
The Allen-Bradley 1791-0A32 is a high-density Block I/O AC output module designed for distributed control systems. This digital output module integrates thirty-two discrete output channels in four groups of eight, providing reliable switching of AC loads such as motor starters, solenoid actuators, indicators, and signaling devices. It supports the Remote I/O (RIO) protocol for direct communication with RIO scanners, functioning as a slave device that mimics a distributed I/O station. The 1791-0A32 is compatible with PLC-2, PLC-3, PLC-5/20, and PLC-5 controllers, making it a versatile choice for legacy automation upgrades.
Technical Specifications Breakdown
Key parameters for the 1791-0A32 are listed below for quick reference:
| Feature | Specification |
|---|---|
| Module Type | Digital AC Output Module |
| Number of Outputs | Thirty-Two (32) outputs |
| Channel Grouping | Four (4) groups of Eight (8) channels |
| Operating Voltage Range | 20-132 VAC |
| Nominal Output Voltage | 120 VAC |
| Maximum On-state Current | 50 mA per output |
| Surge Current | 10 A for 50 ms each, repeatable every 2 sec |
| Output Delay Time, OFF to ON | 1.0 ms at 60 Hz and 1.0 ms at 50 Hz |
| Output Delay Time, ON to OFF | 8.3 ms at 60 Hz or 10.0 ms at 50 Hz |
| OFF State Leakage Current | 3 mA |
| Mounting Orientation | Vertical and Horizontal |
| Weight | 1.00 lbs (0.45 kg) |
Industry Applications
For example, in a bottling plant, the 1791-0A32 can control multiple solenoid valves for filling stations. Its four isolated groups allow independent power distribution, reducing wiring complexity. The 10 A surge current rating supports inrush loads like small motor starters without external suppression. When upgrading older PLC-2 or PLC-5 systems, this block I/O replaces bulky racks, saving cabinet space and simplifying maintenance.
Installation & Setup Guidance
Mount the 1791-0A32 vertically or horizontally on a DIN rail or panel. Ensure ambient temperature stays between 0 and 60 °C. Connect AC power to terminals L1 (1), N (3), and GND (2). For RIO communication, wire the blue (BLU), clear (CLR), and shield (SHD) terminals on the left side. Set the I/O rack number via the switch assembly behind the front cover. Status LEDs on the front cover aid in initial verification. Always verify that the connected load does not exceed 50 mA per output continuously.
Maintenance & Reliability
Inspect the module periodically for dust accumulation and loose connections. The front cover provides access to status indicators for troubleshooting. Given its discontinued status, stock a spare unit to minimize downtime. Operate within the specified temperature range to ensure reliable switching.
Compatibility & Integration
The 1791-0A32 communicates via Remote I/O (RIO) protocol. It is compatible with scanners such as the 1771-SN (PLC-2 family), 1775-S5 (PLC-3 family), and PLC-5VME (6008-LTV). No external adapter is needed; the module includes built-in adapter functionality. It works with PLC-2, PLC-3, PLC-5/20, and PLC-5 controllers.
Selection Guide & Purchasing Advice
When selecting a replacement for a failed 1791-0A32, consider that this model is discontinued/obsolete. AutoDCSTech offers verified used and new surplus units. Verify current lifecycle status and availability before ordering. For new installations, evaluate modern equivalents from the Allen-Bradley 1734 or 5069 series for extended features and support.
Troubleshooting & Common Issues
If outputs fail to energize, check the RIO communication cable and verify the rack number setting. Use the status LEDs to identify group faults. If an output channel remains on when commanded off, measure leakage current; the module specifies 3 mA off-state leakage, which may keep sensitive loads active. Ensure the load requires at least 50 mA to switch reliably.
Availability & Condition at AutoDCSTech
| Part Number | 1791-0A32 |
|---|---|
| Availability | In Stock |
| Condition | New |
| Warranty | One Year |
| Origin | US |
