Introduction
In the 1990s, machine builders needed a way to connect low-voltage TTL signals directly to PLCs without bulky interface relays. The Allen-Bradley 1769-IG16 answered that call. Today, this 16-point TTL input module remains a practical choice for CompactLogix systems that must read high-speed, current-sourcing signals from encoders, sensors, and specialty controllers. As a current product, it is ready for new builds and spares alike.
What Is the 1769-IG16?
The 1769-IG16 is a 16-point TTL input module from Allen-Bradley, part of the CompactLogix product line. It accepts current-sourcing low-to-true inputs with an operational voltage range of 4.5 to 5.5 Volts DC. Each input point works with TTL logic levels, making the module ideal for interfacing with devices that output standard 5V DC signals. The module uses copper wire rated to 90 degrees Celsius and accepts solid wire sizes from 22 to 14 AWG. It ships with a replacement terminal block option, the 1769-RTBN18.
Technical Specifications
The 1769-IG16 delivers 16 input points in a single-slot width. It draws 120mA at 5.1 Volts DC and dissipates 1.6W during operation. A digital filter offers selectable delay times for both ON-to-OFF and OFF-to-ON transitions: 0 seconds, 100 milliseconds, 500 milliseconds, 1 millisecond, 2 milliseconds, 4 milliseconds, and 8 milliseconds. The input signal delay time is 8 milliseconds, and the module tolerates a 50mV peak-to-peak ripple voltage. OFF-state voltage ranges from 2.0 to 5.5 Volts DC at 4.1mA, while ON-state voltage spans 2 to 5.5 Volts DC. Isolation voltage is 75 Volts DC, with reinforced insulation type-tested at 1697 Volts DC for 1 second between input points and the bus.
Installation and Setup
Mount the 1769-IG16 on a DIN rail or panel using the 6 pound-per-inch terminal screws. It has a supply distance rating of 8 modules, meaning it can sit up to eight modules away from the power supply. The module operates in temperatures from -40 to 85 degrees Celsius (-40 to 185 degrees Fahrenheit) at 5 to 95% non-condensing relative humidity. It functions at altitudes up to 2000 meters (6561 feet) without de-rating and withstands operational shock up to 30G and vibration of 5G at 10 to 500 Hertz. Weighing approximately 250g (0.55 pounds), it measures 118 x 35 x 87 millimeters (4.65 x 1.38 x 3.43 inches).
Why It Matters for Your Operation
When a TTL encoder or specialty sensor needs to talk to a CompactLogix controller, the 1769-IG16 provides a direct, reliable path. Its selectable digital filter helps reject noise in electrically noisy plants, while the wide temperature range suits harsh oil, gas, and industrial environments. For teams facing downtime, having a ready-to-ship spare on the shelf is practical insurance. Oil AutoTech specializes in fast-dispatch spares for oil, gas, and industrial automation, with quick worldwide delivery and hands-on technical selection help.
Selection Guide
Before ordering, verify your system uses CompactLogix and that your field devices output TTL-level signals within 4.5 to 5.5 Volts DC. Confirm the wire size and terminal block compatibility; the 1769-RTBN18 is the replacement terminal block for this module. If you need help matching the 1769-IG16 to your existing I/O configuration, contact Oil AutoTech today for pricing and availability.
