Allen-Bradley 1756-IR6I Isolated Digital Input Module

The Allen-Bradley 1756-IR6I is a six-channel isolated RTD input module for ControlLogix systems, delivering six isolated inputs for RTD sensors with 250 V continuous isolation between input channels and the backplane (and input channel-to-channel) and overvoltage protection up to 24 V AC/DC per input. It uses Sigma-Delta conversion and supports data formats in IEEE 32-bit floating point or left-justified 2’s complement integer, with a channel bandwidth of 15 Hz and a settling time under 80 ms to 5% of full scale. The module is one slot wide, accepts removable terminal blocks 1756-TBNH or 1756-TBSH, and features electronic, software-configurable keying with environmental ratings of North American T4A and IEC T4; firmware version 1.12 is associated with this model. Typical scan times are 25 ms minimum for ohms measurements, 50 ms minimum for temperature readings, and 10 ms minimum when data is in integer format, with calibration recommended every six months and a calibrated accuracy better than 0.1% of range at 25 °C, plus documented drift specs.