Allen-Bradley 1734-IB8 POINT I/O Digital Input Module

The Allen-Bradley 1734-IB8, also cataloged as the 1734-IB8 Digital Input Module, operates as a dedicated hardware component for 24 VDC sinking discrete signal processing within DeviceNet or EtherNet/IP control networks.

Hardware Specifications

EtherNet/IP Bus Communication and I/O Density Scaling

• The module routes 8 discrete sinking input channels across the internal POINT I/O backplane interface, enabling high-density digital signal collection within a compact 12 mm module width footprint. Signal transitions are digitized at the hardware input stage and cyclically packetized for transmission over EtherNet/IP or DeviceNet scanner networks.
• Module configuration parameters, including selectable input filter debounce times and point-level fault latching, are pushed dynamically across the backplane bus during initialization, eliminating physical DIP switch requirements and maintaining deterministic timing execution across distributed racks.

Frequently Asked Questions

Q: What are the backplane current draw restrictions when inserting this module into a POINT I/O terminal base assembly?

A: The module draws up to 75 mA from the 5 VDC POINT I/O backplane bus. Total backplane current must be monitored within the rack assembly; if cumulative current consumption exceeds 1.3 A, a 1734-FPD field power distributor or additional 1734-APB adapter must be installed.

Q: Can this module be removed and inserted under power (RIUP) during active PLC execution?

A: Yes, RIUP is supported when mounted on a 1734-TB or 1734-TBS base assembly. However, removal breaks field wiring continuity for the 8 associated input channels, requiring field devices to be safely isolated prior to module extraction.

Field Installation Guidelines

• Key the 1734-TB or 1734-TBS terminal base before inserting the module into the DIN rail assembly. Align the mechanical keying switch on the base to Position 1 to prevent improper module installation.
• Secure the terminal base onto a standard 35 mm zinc-plated DIN rail (EN 50022), ensuring the integral grounding foot latches firmly against the rail to establish a continuous chassis earth path.
• Wire 24 VDC field sinking input sensors directly to the numbered terminal screws on the removable terminal block, maintaining wire gauge sizes between 0.2 to 2.5 mm sq (24 to 14 AWG).
• Route field input signal lines separately from high-voltage AC cables and inductive motor leads by at least 300 mm inside panel ducting to prevent electromagnetic noise coupling onto the DC input channels.