Reliability in Industrial Output Control
For maintenance engineers managing SLC 500 systems, the Allen-Bradley 1746-OB32 offers a robust solution for discrete output control. This digital DC output module provides thirty-two channels, each rated for 24VDC nominal output, making it suitable for high-current applications like actuating solenoids and pilot lamps. Its design emphasizes ease of service, with a removable terminal block and individual LED indicators per channel for quick troubleshooting.
Technical Specifications Analysis
The 1746-OB32 operates within a voltage range of 5-50 Volts DC, sourcing up to 0.5-0.25 amps per output. Each of the two groups contains sixteen points per common, with a total module current of 8 amps. The backplane current draw is 190 milliamps at 5 Volts, and signal delays are 0.1 ms for ON and 1.0 ms for OFF. These parameters ensure predictable switching for industrial loads.
From a maintenance standpoint, the module's step response of 60 milliseconds in and 2.5 milliseconds out allows for reliable actuation in time-sensitive processes. The electronic protection is not specified, so engineers should implement external fusing as needed. The module's operating temperature range of 0 to 60 degrees Celsius and 5-95% non-condensing humidity support stable performance in typical factory environments.
Application Scenarios and Use Cases
In a typical manufacturing line, the 1746-OB32 can control multiple DC-powered actuators, such as pneumatic valves or conveyor solenoids. Its high-density design saves chassis slots, which is valuable when expanding legacy SLC 500 systems. For example, a packaging machine might use this module to sequence thirty-two individual cylinder movements, with each output driving a solenoid valve.
Another common application is in material handling systems, where the module energizes indicator lights and buzzers for operator alerts. The 1746-OB32's 24VDC output directly interfaces with many industrial pilot devices, reducing the need for interposing relays. Maintenance teams appreciate the clear LED status indicators, which speed up fault diagnosis during line stoppages.
Compatibility and Integration
The 1746-OB32 fits into any slot of a 1746 chassis except slot 0, which is reserved for the processor. It is compatible with both fixed and modular SLC 500 hardware styles. The module uses a removable terminal block, and Allen-Bradley recommends 1746-N3 or 1492 wiring systems for proper termination. This ensures reliable connections and simplifies replacement during maintenance.
For integration, the module communicates over the SLC 500 backplane, drawing 190 mA at 5V DC. No external communication protocols are required, as the module is directly addressed by the SLC processor. Engineers should verify that the backplane current capacity of the chassis is not exceeded when adding multiple modules.
Frequently Asked Questions
What is the output current rating per channel for the 1746-OB32?
Each output channel on the 1746-OB32 is rated for 0.5-0.25 amps at 0-60 degrees Celsius, with a minimum load of 1 mA per channel. The total module current is 8 amps, and each common point can handle up to 2 amps.
Can the 1746-OB32 be used with AC loads?
The 1746-OB32 is a DC output module providing 24VDC nominal output. For AC loads, an interposing relay with a 24VDC coil can be used, with the relay contacts switching the AC circuit. This also provides isolation in noisy electrical environments.
What certifications does the 1746-OB32 hold?
The module is C-UL and UL Listed for Industrial Control Equipment, suitable for Class I, Division 2, Groups A, B, C, D Hazardous Locations. It also meets NEMA standard ICS 2-230 for noise immunity. Please verify current lifecycle status and availability with Petro Auto Tech before ordering.
Company Strength and Supply Assurance
Petro Auto Tech provides genuine Allen-Bradley 1746-OB32 modules with reliable sourcing and fast shipping. Our team understands the importance of minimizing downtime, and we offer support to help you select the right parts for your SLC 500 system.
