Allen-Bradley 1734-OE4C POINT I/O 4-Channel Analog Current Output Module

Four 4-20 mA outputs in one POINT I/O slot

The Allen-Bradley 1734-OE4C provides four analog current outputs for valve positioners, drive speed references and other 4 to 20 mA or 0 to 20 mA loads. Each channel is single-ended and non-isolated, and the output stays at 0 mA until communication with the controller has been established.

It is the high-density counterpart of the two-channel 1734-OE2C. Choose it where more outputs are needed per node and the larger field supply current (220 mA) is available.

Technical specifications

Accuracy, load and response

The sheet lists a resolution of 16 bits over 0 to 21 mA (0.32 microamps per count). Absolute accuracy at the current terminal is at least 0.4%, improving to 0.1% when the channel is calibrated, with a temperature drift below 50 ppm per C. The two-channel module is specified at 0.1% without calibration, so the difference should be checked against the loop requirement.

The output drives 0 to 750 ohm loads, converts in 1 microsecond and reaches 63% of a step in 160 microseconds at most. A surge current of 2 A for 10 ms, repeatable every 3 seconds, is permitted. Power dissipation reaches 2.15 W with shorted (0 ohm) outputs, so allow for the heat when many modules sit together.

Installing and powering the module

Field power is 10 to 28.8V DC including 5% AC ripple, at 220 mA maximum and 110 mA nominal at 24V DC with each output at 20 mA. POINTBus supplies 75 mA. The module fits 1734-TB, 1734-TBS, 1734-TOP, 1734-TOPS and the 3-wire bases, with the keyswitch at position 4.

Wire with shielded copper, 23 to 13 AWG at 100 °C or higher, wire category 2 on signal and 1 on power ports. There is no isolation between outputs or between outputs and field power. The status indicators show network, module and one output state per channel. Remember to keep output wiring away from power cables, and follow the shield-grounding guidance of the wiring and grounding guidelines, publication 1770-4.1.

Documents and quotation

The sheet 1734-IN034 contains the output table and the certification page. Provide the 1734-OE4C reference, quantity, the controller or adapter and the loads on each channel when you request a quotation. Related parts are listed in PLC & I/O Cards.

How the 1734-OE4C Works

The controller writes a value for each channel to the 1734-OE4C through the network adapter and POINTBus. The module’s digital-to-analog converter turns that value into a current that the output stage drives through the field loop, from the module terminal, through the load, and back to the field power common. Because the output is a regulated current source, the signal stays correct regardless of cable resistance, as long as the total loop resistance stays within the 0–750 Ω limit. This is why current outputs are preferred for long runs to valve positioners and drives out in the plant.

In the 4–20 mA range the live zero lets the receiving device detect a broken wire, since it would see 0 mA instead of at least 4 mA. The module also holds its outputs at 0 mA until the controller connection is established, so field devices start from a defined state at power-up.

Selection & Ordering Guide for the 1734-OE4C

• 1734-OE4C – four current outputs, 0–20 mA or 4–20 mA.
• 1734-OE4CK – conformal-coated version.
• 1734-OE2C – two current outputs, with higher uncalibrated accuracy.
• 1734-OE2V – two voltage outputs, 0–10 V or ±10 V, for devices with voltage inputs.

Each module needs a POINT I/O terminal base with the keyswitch at position 4 and an adapter at the head of the node. Check the input resistance of every receiving device and add the cable resistance to confirm the loop stays within 750 Ω. Our team can help confirm the correct ordering code when you request a quote.

Installation & Maintenance of the 1734-OE4C

• Size the field power supply for the 220 mA maximum draw of each module, in addition to any other modules on the same field power bus.
• Since the outputs are not isolated from each other, use a signal isolator for any receiving device whose input is referenced to a different earth.
• POINT I/O supports removal and insertion under power, but only when the area is known to be non-hazardous.
• Where the application needs the tighter 0.1% figure, calibrate the channels as described in the Rockwell documentation and record the results.
• At commissioning, measure each loop with a calibrated meter at 4, 12 and 20 mA and check that the actuator moves to the matching position.

Typical Applications in Oman & the GCC

The 1734-OE4C commonly drives control valve positioners on water transmission and desalination plants, speed references to variable-frequency drives on pumps and cooling-tower fans, damper actuators in HVAC and district cooling systems, and set-points for burner and dosing controls in process skids. Four outputs in one 12 mm slot allow a compact remote I/O panel close to the process, with only a network cable back to the control room.

Why Source from Seven Star LLC

Seven Star LLC is an independent supplier in Muscat. Seven Star LLC supplies Allen-Bradley POINT I/O and other automation components across Oman and the GCC. Send the 1734-OE4C catalog number, the quantity and the loads on each channel and request a quote; our team can help confirm the correct ordering code, terminal base and adapter.