1734-ow4_a_digital_contact_module

Description

Technical Specifications

Main Features and Advantages

True dry-contact relay outputs for AC/DC flexibility: The Allen-Bradley 1734-OW4​ provides genuinely isolated N.O. relay contacts, not simulated solid-state switches. This means each output channel can switch AC or DC loads within its voltage/current rating without regard to polarity or supply type—ideal for panels that mix 24 V DC pilot devices with 120 V AC control relays or small contactor coils.Galvanic isolation protects the control system: Each relay contact set on the Allen-Bradley 1734-OW4​ is isolated from the I/O backplane electronics by 250 V working isolation (Hi-Pot tested to 2550 V DC), and contacts are mutually isolated from one another. This galvanic separation prevents high-voltage transients on the load side from coupling back into the 5 V DC logic bus, enhancing system robustness in electrically noisy plant environments.Per-point LED diagnostics and RIUP support: Four individual green LEDs on the Allen-Bradley 1734-OW4​ show the energized/de-energized state of each relay, allowing technicians to quickly correlate ladder logic output bits with physical contact closure during commissioning or fault finding. The module can be removed and reinserted under power (Remove and Insert Under Power) when mounted on a powered POINT I/O rack, facilitating hot-swap replacement without shutting down the entire station.Compact footprint with standard terminal base ecosystem: At only 12.5 mm wide, the Allen-Bradley 1734-OW4​ consumes minimal DIN-rail space yet delivers four fully independent relay outputs. It shares the same terminal bases (screw or spring-clamp) with other 1734 analog and discrete modules, letting designers standardize on one wiring method across an entire distributed I/O node and reducing spare-parts inventory.Seamless POINT I/O network integration: The Allen-Bradley 1734-OW4​ works with any POINT I/O communication adapter—EtherNet/IP (1734-AENT / 1734-AENTR), ControlNet (1734-ACNR), DeviceNet (1734-ADN), or PROFIBUS DP (1734-PDN)—and is auto-discovered and configurable in Studio 5000 Logix Designer, including electronic keying and rack optimization settings for reliable data exchange with the controller.

Application Field

The Allen-Bradley 1734-OW4​ is widely used in distributed I/O nodes where the controlled devices require isolation from the control voltage or where load types vary between AC and DC within the same enclosure. In conveyor and material-handling systems, the Allen-Bradley 1734-OW4​ typically drives 24 V DC indicator stacks, audible buzzers, and pneumatic solenoid bank enable relays, while one or two channels may simultaneously control 120 V AC motor starter auxiliary coils or local HVAC dampers—all from a single compact module located close to the field devices, reducing long homerun wires back to a central cabinet.Packaging machinery and converting lines employ the Allen-Bradley 1734-OW4​ to actuate guard-door release solenoids, stamp “batch-complete” signals to panel-mounted tower lights, or trigger external counters and printers that expect a dry-contact closure rather than a sourced 24 V DC PNP signal. Because the relay contacts are polarity-independent, the same module can be specified on bill-of-materials for machines destined for both 24 V DC and 120 V AC control-voltage markets without change.In process skids, water/wastewater lift stations, and building automation subsystems, the Allen-Bradley 1734-OW4​ is often the preferred choice for interfacing PLC logic with legacy equipment—such as motorized dampers, pump run permissives, or local annunciator panels—that were originally designed to be switched by a mechanical contact rather than a solid-state output. Its ability to tolerate minor inductive kickback (when used with appropriate flyback diodes or snubber circuits on the load side) and its visible point-level LEDs make it a practical, diagnosable interface between modern distributed I/O networks and traditional electromechanical control elements.