1746-IG16 Allen-Bradley SLC 500 Digital DC TTL Input Module
Product Introduction
The 1746-IG16 module belongs to the SLC 500 series from Allen-Bradley. It provides 16 sourcing input channels designed specifically for Transistor-Transistor Logic (TTL) signals. The voltage range is 4.5 to 5.5V DC with a nominal 5V DC. You can use this I/O module to interface with electronic devices, BCD encoders, or other TTL-level signal sources. Its fast switching speed makes it ideal for precision control applications.
Technical Specifications of the 1746-IG16
The Allen-Bradley 1746-IG16 accepts sourcing inputs with a ripple voltage of 50 mV peak-to-peak. The module draws 140 mA from the 5V DC backplane. Signal delay is extremely fast: 0.25 milliseconds for ON state and 0.5 milliseconds for OFF state.
The off-state voltage range sits between 2 and 5.5V DC, with an off-state current of 4.1 mA. Nominal input current per point is 3.7 mA. Power dissipation is only 0.02W per point, with total module dissipation at 1W (minimum 0.7W).
Circuit electro-optical isolation is tested at 1500V between control logic and input terminals. Noise immunity meets NEMA ICS 2-230 standards. The 1746-IG16 works with I/O connection accessories 1746-HT and 1746-HCA. For octal wiring, use kit 1746-RL42. The removable terminal block option is 1746-RT25B. Step response is 100 ms in and 2.5 ms out.
Important TTL logic behavior: At low voltage levels (-0.2 to 0.8V DC), the input is considered ON. This inverse functionality differs from standard DC input modules.
Mechanical and Environmental Ratings
The 1746-IG16 operates between 0°C and 60°C (32°F to 140°F) at 5-95% non-condensing humidity. Storage temperature ranges from -40°C to 85°C (-40°F to 185°F).
Vibration tolerance is 2.5G at 57–200 Hz with 0.015 inches peak displacement. Shock resistance reaches 30G. These ratings ensure reliable operation in demanding industrial environments.
Frequently Asked Questions (FAQ)
1. What is the main application for the 1746-IG16?
The 1746-IG16 is designed for TTL (Transistor-Transistor Logic) and BCD input signals from electronic devices, encoders, and digital circuits operating at 5V DC.
2. How fast is the 1746-IG16 compared to standard DC modules?
It is much faster. The 1746-IG16 has an ON delay of only 0.25 milliseconds, whereas standard DC modules typically have 4-8 ms delays. This makes it suitable for high-speed counting and positioning.
3. Does the 1746-IG16 work with 24V DC sensors?
No, the 1746-IG16 accepts only 4.5-5.5V DC sourcing signals. For 24V DC applications, consider the 1746-IB8 or 1746-IC16 instead.
4. Why does the 1746-IG16 consider low voltage as ON?
This is standard TTL logic behavior. For the 1746-IG16, a signal between -0.2V and 0.8V DC turns the input ON. A high signal (2V to 5.5V DC) turns it OFF.
5. Can I mix the 1746-IG16 with other SLC 500 modules?
Yes, the 1746-IG16 is fully compatible with other SLC 500 I/O modules. However, group similar module types together for easier maintenance and wiring organization.
