The PACSystems RX3i analog input module family provides 4-channel voltage and current measurement in the IC694 (90-30 compatible) form factor. Three variants cover most industrial analog sensing applications, from basic 4-20mA loop monitoring to high-resolution universal inputs.

Which RX3i analog input module fits the application?

The IC694ALG221 is a current-only module (4-20mA/0-20mA) with 12-bit resolution and hot-swap capability — ideal for standard process transmitter loops where module replacement without rack power-down matters. The IC694ALG220A adds voltage input (±10VDC) on every channel at 16-bit resolution, with software-configurable per-channel mode selection, at the cost of hot-swap support. For applications needing both analog input and output, the IC694ALG442 combines four inputs with two outputs in a single slot, all at 12-bit resolution.

What do all variants share?

Every module uses isolated differential inputs to reject common-mode noise on long field wiring runs, with 250VAC continuous isolation between the field terminals and the RX3i backplane. All four channels update within 2-4ms depending on model, and twisted shielded cable is recommended for field wiring. Modules mount in any standard IC694 universal backplane slot and carry UL, CE, ATEX Zone 2, and marine classification approvals.