Product Overview
From a maintenance engineer's perspective, the Allen-Bradley 1794-OB16 Flex I/O Digital DC Output Module offers reliable discrete output control for distributed automation systems. This module features sixteen sourcing output channels at 24VDC nominal, making it a solid choice for controlling actuators, relays, and indicators in harsh industrial environments. Its open-type enclosure and DIN rail mounting simplify installation and service access.
Technical Specifications Breakdown
Key parameters for the 1794-OB16 are listed below for quick reference:
| Feature | Specification |
|---|---|
| Output Type | Digital DC Output Module |
| Number of Outputs | 16, sourcing |
| On-state Voltage, nom. | 24VDC |
| On-state Voltage, min. | 10VDC |
| On-state Voltage, max. | 31.2VDC |
| Output Current Rating | 8.0A |
| On-state Current, max. | 500mA per Channel |
| On-state Voltage Drop, max. | 0.5V DC |
| Off-state Leakage Current, max. | 0.5mA |
| Isolation Voltage | 50V Continuous |
| Flexbus Current | 80mA @ 5V DC |
| Power Dissipation | 5.3W @ 31.2V DC max. |
| Thermal Dissipation | 18.1 BTU/hr. @ 31.2V DC max. |
| Operating Temperature | 0 to 55 C (32 to 131 F) |
| Storage Temperature | -40 to 85 C (-40 to 185 F) |
| Vibration | 5g @ 10 to 500 Hz |
| Operating Shock | 30 g |
| Indicators | 16 Yellow status indicators |
| Mounting | DIN Rail |
Industry Applications
This digital output module is ideal for discrete control in manufacturing lines, material handling, and packaging systems. The 16 sourcing channels can drive solenoid valves, motor contactors, and indicator lights, while the 500mA per channel capacity handles moderate loads. The 50V continuous isolation voltage ensures reliable operation in mixed-voltage cabinets, reducing noise coupling.
Installation & Setup Guidance
Mount the 1794-OB16 on a standard DIN rail using the open-type enclosure. Select a compatible terminal base from the supported list: 1794-TB2, 1794-TB3, 1794-TB3S, 1794-TB3K, or 1794-TB3SK. Wire size is determined by the installed terminal base. Ensure the keyswitch position is set to 2 for proper alignment. Up to eight modules can be installed in a single Flex I/O rack. The module does not include internal fusing; install external fuses per system requirements.
Maintenance & Reliability
Inspect the module periodically for dust accumulation and loose connections. The 16 yellow status indicators provide quick visual feedback on each channel's state. Operating temperature range of 0 to 55°C ensures stable performance in typical industrial enclosures. The 5g vibration rating and 30g shock rating support reliable operation in machinery with moderate vibration.
Compatibility & Integration
The 1794-OB16 works with any 1794 Flex I/O adapter for distributed I/O applications. It can also serve as local I/O for FlexLogix controllers or the FlexLogix local I/O extender (1794-FLA). This flexibility simplifies system expansion and reduces wiring costs.
Selection Guide & Purchasing Advice
When selecting this module, verify your system voltage matches the 24VDC nominal on-state voltage. For sourcing output configurations, the 1794-OB16 is a proven choice. Contact SpareTechPLC for current lifecycle status and availability before ordering.
Troubleshooting & Common Issues
If a channel fails to energize, check the corresponding yellow status indicator. Verify the terminal base connection and external wiring. Ensure the load does not exceed 500mA per channel. If multiple channels are off, inspect the FlexBus current (80mA @ 5V DC) and power dissipation limits.
