Allen-Bradley 1734D-IA8XOW8 POINTBlock DeviceNet I/O Module

Configured for discrete signal interface execution in DeviceNet fieldbus architectures, the Allen-Bradley 1734D-IA8XOW8 (1734D-IA8XOW8 Digital Combination Module) provides direct physical/electrical execution.

Hardware Specifications

DeviceNet Communication and I/O Density Scaling

• The module integrates 8 discrete 120 VAC inputs and 8 relay outputs within a single self-contained POINTBlock enclosure, eliminating the requirement for individual backplane base expansion modules. Communication across the DeviceNet network is managed via software-configurable baud rates of 125 kbps, 250 kbps, and 500 kbps, featuring auto-baud identification upon network initialization.
• Deterministic network performance is maintained through standard DeviceNet I/O messaging structures, supporting Change-of-State (COS), Cyclic, and Polled I/O triggers. Internal logic circuitry processes input debounce filtering and output state switching while transmitting diagnostic bit status directly to the primary controller over the trunk line.

Frequently Asked Questions

Q: What are the primary installation limits regarding DeviceNet network power and drop cable lengths for this module?

A: The module draws operational power directly from the 24 VDC DeviceNet trunk network. Drop line lengths must not exceed 6 meters (20 feet) for standard thin cable connections, while total trunk cable distance remains constrained by the selected network baud rate (500 meters at 125 kbps, 250 meters at 250 kbps, and 100 meters at 500 kbps).

Q: Can relay output channels be field-serviced or hot-swapped individually during active operation?

A: Hot-swapping individual channels is not supported on POINTBlock monolithic units. The terminal block assembly must be completely de-energized before removing field wiring or dismounting the block from the DIN rail to prevent electrical arcing across 120 VAC input and relay contact nodes.

Field Installation Guidelines

• Mount the module vertically or horizontally onto standard 35 mm DIN rail (EN 50022). Ensure grounding spring clips make direct, unpainted metal contact with the DIN rail to establish an effective earth path.
• Maintain a minimum clearance of 50 mm (2 inches) on all sides of the housing to permit passive thermal heat sink dissipation and allow unhindered routing of field wiring harnesses.
• Terminate DeviceNet network wiring using approved sealed 5-pin mini-style or micro-style connectors, adhering strictly to color-coded signal line protocols (V+, CAN High, Shield, CAN Low, V-).
• Verify that field input wiring for 120 VAC circuits is separated from low-voltage DC communication lines by a minimum distance of 300 mm inside cable trays to eliminate capacitive cross-talk interference.
• Ensure both physical ends of the DeviceNet trunk line are terminated with standard 121 Ohm, 1/4 Watt metal film terminating resistors connected across CAN High and CAN Low conductors.