The Bidirectional RS422 to TTL Converter Module is a compact, full-duplex protocol converter designed to bridge RS422 differential signals with 5V TTL-level UART signals from microcontrollers. Built around a reliable RS422 transceiver chip, this module enables long-distance, noise-immune serial communication between 5V microcontrollers (Arduino Uno, Nano, Mega, etc.) and industrial RS422 devices, sensors, and equipment.
At the heart of the module is a full-duplex RS422 transceiver that provides one driver and one receiver, supporting simultaneous transmit and receive operation. This is a key advantage over half-duplex RS485, making the module ideal for applications requiring continuous bidirectional data flow. The bidirectional design means the module can convert signals in both directions simultaneously — TTL to RS422 for outgoing data, and RS422 to TTL for incoming data.
The module performs bidirectional signal conversion:
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TTL to RS422 — Converts 5V TTL UART signals from your microcontroller to differential RS422 signals for long-distance transmission.
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RS422 to TTL — Converts incoming differential RS422 signals back to 5V TTL levels for your microcontroller to read.
The RS422 differential signaling provides excellent common-mode noise rejection and allows cable runs of up to 1200 meters (at lower data rates), far exceeding the range of standard TTL or RS232 interfaces. The module supports data rates up to 2.5 Mbps, making it suitable for high-speed serial communication.
The module is specifically designed for 5V logic systems, making it directly compatible with classic Arduino boards and other 5V microcontrollers without the need for level shifting. This simplifies integration and ensures reliable operation with 5V logic. The module is not 3.3V compatible on the TTL side — do not connect 3.3V logic directly without level shifting.
The module includes screw terminals for secure connection of the RS422 A, B, Y, and Z differential lines, and pin headers for easy connection to your microcontroller’s UART pins (TX, RX, VCC, GND). LED indicators provide visual feedback for power and data activity, making it easy to verify operation during setup and troubleshooting.
The board operates from a 5V supply, with low power consumption suitable for a wide range of applications. The compact PCB design with mounting holes allows easy integration into control panels, DIN rails, and equipment enclosures.
The module is widely used in industrial automation, long-distance serial communication, motor control, PLC interfacing, data acquisition systems, security systems, and any application where reliable, noise-immune serial communication is required over extended distances with 5V logic.
Important Note: The RS422 standard uses four wires (TX+, TX-, RX+, RX-) for full-duplex communication. Ensure proper termination (typically 120Ω) at the far end of long cable runs to minimize signal reflections. Use twisted-pair cable for best noise immunity. The module is not compatible with RS485 without additional wiring configuration, as RS485 is typically half-duplex.
Whether you are connecting a 5V microcontroller to an industrial RS422 device, extending serial communication over long distances, or building a noise-immune data link, the Bidirectional RS422 to TTL Converter Module provides a reliable, well-supported solution. It is suitable for individual engineers, students, and businesses purchasing in bulk for product development or industrial applications.
Features
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Full-duplex RS422 communication — Simultaneous transmit and receive
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Bidirectional conversion — TTL to RS422 and RS422 to TTL simultaneously
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5V logic compatible — Direct interface with Arduino Uno, Nano, Mega, and other 5V microcontrollers
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High data rate — Up to 2.5 Mbps
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Long-distance support — Cable runs up to 1200 meters (at lower data rates)
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Excellent noise immunity — Differential signaling rejects common-mode noise
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Screw terminals — Secure RS422 A/B/Y/Z connections
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Pin headers — Easy UART connection to microcontroller
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LED indicators — Power and data activity feedback
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Compact PCB design — With mounting holes for easy installation
Technical Specifications
| # | Parameter | Specification |
|---|---|---|
| 1 | Interface Type | RS422 to TTL (full-duplex, bidirectional) |
| 2 | Logic Voltage | 5V TTL |
| 3 | Data Rate | Up to 2.5 Mbps |
| 4 | Supply Voltage | 5V DC |
| 5 | RS422 Connections | A, B, Y, Z (screw terminals) |
| 6 | TTL Connections | TX, RX, VCC, GND (pin headers) |
| 7 | Cable Length | Up to 1200m at lower data rates |
| 8 | Module Dimensions | Compact PCB with mounting holes |
