Allen-Bradley 1738-IE4CM12/A ArmorPoint I/O Module

The Allen-Bradley 1738-IE4CM12/A, also cataloged as the 1738-IE4CM12/A Analog Input Module, serves as a dedicated hardware component for acquisition of 0-20 mA and 4-20 mA loop current signals within ArmorPoint distributed I/O networks. Configured for analog current sampling in segmented field I/O architectures, the Allen-Bradley 1738-IE4CM12/A provides direct physical-to-digital conversion of four single-ended input channels through a 24 VDC backplane supply structure.

Suffix Breakdown & Model Matrix

The 1738-IE4CM12/A model designation is structured as a single catalog identifier within the ArmorPoint (Bulletin 1738) family. No additional functional sub-code segmentation is defined for analog input channel configuration or environmental rating; all operational parameters are fixed at module level.

Hardware Specifications

Backplane I/O Density and Deterministic Update Behavior

Within Allen-Bradley ArmorPoint distributed control architecture, the 1738-IE4CM12/A interfaces with the backplane communication layer supporting change-of-state (COS) update execution. I/O refresh cycles are synchronized across Profinet or EtherNet/IP transport layers, enabling deterministic data sampling across modular field nodes. Channel density scaling is constrained by backplane current budget allocation and module grouping topology.

Frequently Asked Questions (FAQ)

Q: Does the 1738-IE4CM12/A support hot-swap under energized conditions?
A: Yes. The module supports RIUP (Removal and Insertion Under Power), but input channels must be in a non-critical state to avoid transient signal misinterpretation during reconnection.

Q: What is the resolution behavior for low-current signal ranges?
A: The module provides 16-bit signed resolution across 0-20 mA and 4-20 mA ranges, with quantization applied at the A/D conversion stage per channel.

Q: Can the module operate without an external enclosure due to IP rating?
A: The housing is rated up to IP69K; enclosure-free operation is permitted if M12 sealing integrity and cable gland torque specifications are maintained.

Field Installation Guidelines

M12 connectors must be fully torqued to ensure sealing continuity across IP-rated interfaces. Signal cables shall be routed with separation from high-voltage conductors to reduce inductive coupling into 4-20 mA loops. Shield termination must be grounded at one defined system point to avoid ground loop current injection. During installation, maintain mechanical strain relief at cable entry points to prevent connector micro-movement under vibration loading. Module replacement under RIUP conditions must ensure stable loop current before insertion or removal.