Allen-Bradley 1746-NI8 Analog Input Module for SLC 500

The Allen-Bradley 1746-NI8 is an eight-channel analog input module for the SLC 500 system, delivering 16-bit per-channel resolution across eight inputs. The module is powered from the SLC 500 backplane, drawing up to 200 mA from the 5 V rail and up to 100 mA from the 24 V rail, with a maximum backplane power consumption of 3.4 W. It features nine green LEDs (one per channel and a module-status LED) for quick status indication. Wiring uses a removable terminal block (1746-RT25G), with Belden 8761 cables (or equivalent) recommended, and each terminal accepts up to two 14 AWG conductors. In performance terms, the NI8 provides an update time of about 6 ms and a bandwidth of 1–75 Hz, with a channel input impedance of 250 ohms. The module can be installed in any slot of a Rockwell SLC 500 modular rack and communicates via the backplane as part of the controller I/O. Note that Rockwell has discontinued the SLC 8-point analog input line, including the 1746-NI8, as of September 30, 2024, and it is no longer offered for sale by Rockwell.