Product Summary
The 1794‑IH16 FLEX I/O module provides 16 high‑voltage DC sinking inputs. It operates at a nominal 125VDC and carries North American Hazardous Location approval. This module offers reliable digital signal acquisition for demanding automation systems.
Step‑by‑Step Installation Guide
Mechanical Mounting
Mount the 1794‑IH16 on a standard DIN rail. Position the terminal base at a slight angle and hook it over the top of the rail. Slide the module against the adjacent adapter and push the base downward until it locks into place. Ensure the FlexBus connector engages fully.
Selecting the Correct Terminal Base
The module works with any 1794 series terminal base, such as the 1794‑TB3. The 1794‑TB3 provides three screw‑clamp terminal strips for I/O, common, and supply connections. Use the 18 terminals on the middle strip for –V common and the bottom strip for +V supply.
Wiring Digital Inputs
Connect each field device to one of the 16 input terminals on the top strip. The module sees a minimum on‑state voltage of 90VDC and a nominal of 125VDC. Maximum on‑state voltage is 146VDC. Off‑state voltage must stay below 20VDC.
Current Ratings and Power Dissipation
Each input draws a nominal 2mA at 125VDC. Minimum on‑state current is 1mA; maximum is 3mA. Off‑state leakage does not exceed 0.8mA. The module dissipates up to 6 Watts at 146VDC, which translates to 20.47 BTU per hour.
Hazardous Location Approval
This module carries North American Hazardous Location Approval. It is suitable for Class I, Division 2 areas where flammable gases or vapors may be present. Installation must follow applicable national and local electrical codes.
Compatibility and System Integration
The 1794‑IH16 works with all FLEX I/O adapters and terminal bases. It pairs with 1794‑TB3, ‑TB3S, ‑TB3K, and ‑TB3SK bases. Daisy‑chain power and common through the designated +V and –V terminals to adjacent modules without extra wiring.
