Product Description
Honeywell TC-MUX021 Serial Interface Module
The Honeywell TC-MUX021 (Part Number 51404391-125) is a highly reliable Serial Interface Module engineered specifically for the Honeywell TDC 3000 control system. This module facilitates seamless serial data transmission and robust communication within your industrial automation network. It is equipped with clear front-panel status indicator LEDs—labeled A, B, and OK—allowing for quick visual diagnostics and real-time system monitoring. Built for demanding industrial environments, the unit operates efficiently across multiple voltage ratings, ensuring versatile integration and continuous operational stability.
Technical Specifications:
- Brand: Honeywell
- Model Number: TC-MUX021
- Part Number: 51404391-125 (Rev. C) / 51309283-400 (Rev. H)
- System Compatibility: Honeywell TDC 3000
- Power Requirements: 1.5A @ 12VDC / 1.5A @ 5VDC / 0.3A @ 24VDC
- Diagnostics: Status Indicator LEDs (A, B, and OK)
- Country of Origin: Made in USA

Honeywell TC-MUX021 Serial Interface Module
Optimize your TDC 3000 network with the Honeywell TC-MUX021 (51404391-125) Serial Interface Module. This authentic, USA-made industrial control component features reliable serial data transmission, multi-voltage support (5V/12V/24V DC), and built-in LED diagnostics for seamless automation performance.






