Technical Specifications

FAQ

1. What is the main function of the Allen Bradley 2080-OB4 module?
The 2080-OB4 is a four-point digital DC output module for the Micro800 platform. It provides transistor-based source outputs for controlling external DC loads such as indicator lamps, interposing relays, solenoid valves, contactor interfaces, and other discrete actuators. Each output can be controlled independently by the Micro800 controller according to the application program.

2. Is the 2080-OB4 a source or sink output module?
The 2080-OB4 uses source outputs. When an output is switched ON, the module supplies positive DC voltage to the connected load. The load should therefore be wired between the output terminal and the appropriate DC common. Correct source-output wiring is important because connecting the load according to a sink-output arrangement can prevent the device from operating correctly.

3. What voltage range can the 2080-OB4 handle?
The module is designed for DC operation within a 10.8–30 V DC power supply range. The output specifications identify 24 V DC as the nominal operating voltage, with an allowable output voltage range of approximately 10–30 V DC. The actual field supply should remain within the specified limits to maintain reliable switching and avoid excessive electrical stress.

4. How much current can each 2080-OB4 output handle?
Each output supports up to 0.5 A in steady-state operation. The module can also accommodate a surge current of approximately 2 A for a minimum of 2 seconds. When selecting a load, engineers should consider both its normal operating current and its inrush or starting current. Loads approaching the maximum rating should also be evaluated for temperature, duty cycle, and switching frequency.

5. Does the 2080-OB4 provide short-circuit protection?
The 2080-OB4 does not provide dedicated short-circuit protection for its outputs. For this reason, the external circuit should be properly protected and wired according to the application requirements. If an output is connected to a shorted or excessively high-current load, the output transistor can be subjected to electrical and thermal stress.

6. Can the 2080-OB4 drive solenoid valves or relay coils?
Yes, the module can be used for suitable DC loads such as solenoid valves and relay coils, provided the load voltage and current remain within the output specifications. Inductive loads require particular attention because switching them can generate voltage transients. Appropriate suppression components, such as a flyback diode or another suitable transient-suppression device, should be selected according to the load and control-circuit design.

7. What should I check if a 2080-OB4 output does not turn on?
First check whether the corresponding yellow status LED changes when the controller commands the output ON. Then verify the DC supply voltage, common connection, output wiring, and load continuity. Check that the load current does not exceed the permitted output rating and that the wiring matches the source-output configuration. If the controller indicates that the output is ON but the field device remains inactive, measuring the voltage directly at the output terminal under load can help distinguish a wiring problem from a field-load problem.

8. Can the 2080-OB4 be used for safety-critical output control?
The 2080-OB4 is a standard digital output module and should not be treated as a safety-rated output device. Applications requiring safety functions, such as emergency shutdown or personnel-protection circuits, should use appropriately certified safety hardware and architectures. The 2080-OB4 can still be used for standard machine-control functions where the required safety functions are implemented separately.