Description
The 1734-OE2C is a 2-channel, non-isolated analog current output module engineered for the Allen-Bradley POINT I/O platform. It converts digital count values from a controller chassis into standardized, high-resolution 0 to 20 mA or 4 to 20 mA analog signals to drive proportional control valves, variable frequency drives (VFDs), current-to-pneumatic (I/P) transducers, and analog chart recorders. The module mounts vertically onto a 1734-TB or 1734-TBS terminal base assembly, functioning as distributed I/O over EtherNet/IP, ControlNet, or DeviceNet networks via an upstream network adapter.
Commercial Availability & Procurement
- Condition: Factory Sealed / New Original (New Surplus)
- Warranty: 12-Month Comprehensive Technical Warranty
- Availability: In Stock / Ready for Dispatch
- Estimated Lead Time: 1–3 business days via DHL/FedEx Express International Priority
- Pricing Policy: Spot market pricing varies depending on global factory allocations and component lead times. Contact our commercial sales desk for a definitive, formal quote.
Technical Specifications
| Parameter | Specification |
| Manufacturer | Rockwell Automation / Allen-Bradley |
| Model Series | POINT I/O |
| Catalog Number | 1734-OE2C |
| Outputs per Module | 2 single-ended, non-isolated channels |
| Output Current Range | 4 to 20 mA or 0 to 20 mA (Software configurable) |
| Digital Resolution | 13 bits over 0 to 21 mA (approx. 2.56 µA/bit) |
| Absolute Accuracy | 0.1% Full Scale at 25 °C (77 °F) |
| Accuracy Drift with Temp. | Less than 30 ppm/°C |
| Maximum Loop Impedance | 0 to 750 Ω |
| Conversion Rate | 16 ms (all channels) |
| POINTBus Current | 75 mA maximum at 5 V DC |
| External Power Supply | 24 V DC nominal (10 V DC to 28.8 V DC acceptable range) |
| External Power Current | 70 mA maximum at 24 V DC |
| Terminal Base Screw Torque | 0.6 Nm (5 to 7 lb-in) on 1734-TB assembly |
| Operational Temperature | −20 to +55 °C (−4 to +131 °F) |
System Integration & Real-World Field Constraints
Channel Grounding and Non-Isolation
The 1734-OE2C utilizes single-ended, non-isolated outputs. Both channels share a common internal signal return line (C) which links directly to the 24 V DC field power chassis rail.
Field Engineering Note: Because the channels lack channel-to-channel isolation, ground loops are a frequent issue when interfacing with field devices powered by separate, non-isolated external power grids. If a field actuator or VFD input board exhibits a different ground potential than the POINT I/O rack, your output signal will drift, fluctuate erratically, or trip a “broken wire” diagnostic fault.
- Best Practice: When driving field devices with isolated internal inputs, run shielded twisted-pair cabling and ground the shield only at the POINT I/O chassis end.
- Mitigation: If the field device is non-isolated and tied to a separate ground plane, install an external 4-to-20 mA signal isolator between the 1734-OE2C terminal block and the receiver.
Backplane Power Calculations and Keying
The module draws 75 mA from the 5 V DC POINTBus backplane logic rail. When adding analog modules to a distributed POINT I/O drop, sum the current draw of all modules in Studio 5000 Logix Designer or Integrated Architecture Builder (IAB). Exceeding the 5 V DC capacity of the network adapter module (e.g., a 1734-AENTR) will drop the logic voltage, triggering intermittent communication faults on downstream modules. Insert a 1734-EP24DC expansion power unit before hitting the backplane current limit.
Before sliding the 1734-OE2C into the terminal base, set the mechanical base keying wheel to Position 4 (Analog Output configuration). Attempting to force the module into a base keyed for digital modules (such as Position 1) will damage the internal physical mating pins.
Frequently Asked Questions
Why does the “NODE” or “CH0/CH1” status LED blink red during initialization?
A flashing red channel status LED indicates a configuration error or an open-loop condition (Broken Wire fault). The 1734-OE2C actively monitors the loop current circuit resistance. If the terminal screw is loose, the field cable is severed, or the loop impedance exceeds 750 Ω, the drive electronics cannot force the commanded current, tripping the fault. Check circuit continuity with a multimeter inline in mA mode to confirm loop completion.
Can I program the 1734-OE2C to hold its last output value if network communication is lost?
Yes. The module supports configurable “Fault Mode” states inside the Studio 5000 controller module profile. You can configure each channel independently to execute one of three actions upon a network connection loss:
- Go to Low Scale: Forces the output to 0 mA or 4 mA immediately.
- Hold Last Value: Retains the exact mA output rate measured the instant communication dropped.
- Go to Fault Value: Drives the output to a specific, custom-defined safety value (e.g., 12 mA for a 50% valve position).
How do I configure scaling from engineering units (e.g., 0 to 100% flow) to the module’s RAW digital counts?
Unlike larger Logix platforms (such as ControlLogix 1756 analog cards), the POINT I/O 1734-OE2C does not perform complex onboard engineering unit scaling. The module expects an integer data type from the controller processor.
- For a 4 to 20 mA range configuration, the module scales linearly between raw count values where 4 mA corresponds to a specific integer minimum, and 20 mA corresponds to the maximum integer limit.
- Perform all physical scaling (such as mapping a 0.0 to 100.0% floating-point HMI value to the module’s target integer output data tag) inside the PLC routine utilizing a standard
SCL(Scale) orSCP(Scale with Parameters) instruction block before sending the value to the output tag array.
Allen-Bradley 1734-IB8 Rockwell 2198-D012-ERS3 Allen-Bradley 80190-580-01-R
