Description

Waveshare Industrial 8-Ch PWM Input Module Isolated RS485 Interface is an industrial Modbus RTU module designed for PWM pulse frequency and duty cycle acquisition across 8 isolated input channels. It uses an RS485 interface, supports wide input voltage, and is built for stable operation in industrial environments where anti-interference, isolation, and reliable long-distance communication matter.

This module is a practical fit for control cabinets, industrial monitoring, PLC expansion, motor and fan signal monitoring, production line data collection, and other automation tasks that need accurate PWM measurement over Modbus RTU.

Features

• 8-channel PWM input acquisition for pulse frequency and duty cycle detection.
• RS485 interface with standard Modbus RTU protocol for industrial system integration.
• Wide voltage input with DC 7~36V power supply support.
• High-speed optocoupler isolation for high-frequency detection and stronger signal isolation.
• Power and signal dual isolation for improved reliability and anti-interference performance.
• TVS, resettable fuse, and protection circuits for surge suppression, over-voltage, over-current, lightning, and ESD protection.
• Configurable device address from 1~255 for multi-device RS485 bus deployment.
• DIN rail mounting and stacking installation support for industrial cabinets.
• Onboard watchdog and status LEDs for more stable field operation.

Specifications

Applications

This industrial PWM input module is suitable for factory automation, motor speed signal monitoring, fan control feedback, PLC and SCADA expansion, industrial data acquisition, control cabinet integration, and multi-node RS485 measurement systems. It is especially useful when you need isolated Modbus RTU PWM monitoring across multiple channels in electrically noisy environments.

Product List

1. Modbus RTU PWM Input 8CH 1
2. Power supply terminal adapter 1
3. Screwdriver 1

Other Content

The module is built with industrial deployment in mind. In addition to isolated RS485 communication, it supports rail mounting and stacking, making it easier to build larger modular systems inside a control cabinet or industrial enclosure.

Resources

• Waveshare Modbus RTU PWM Input 8CH Wiki
• Modbus Protocol Specifications
• RS485 Interface Reference
• Raspberry Pi Documentation
• Arduino Language Reference

FAQ

What does this module measure?
It is designed to measure PWM pulse frequency and duty cycle across 8 input channels and report the values over Modbus RTU via RS485.

Is it suitable for industrial environments?
Yes. It includes power and signal isolation, TVS protection, resettable fuse protection, and a DIN rail mount housing for more reliable industrial deployment.

Can multiple modules be used on the same RS485 bus?
Yes. The device address is configurable from 1 to 255, so multiple modules can be cascaded on the same RS485 network.

What similar products should I compare it with?
If you are building a broader industrial control system, you can also compare other Waveshare industrial RS485 and Modbus modules in your catalog, especially related isolated IO, relay, and acquisition modules for matching cabinet deployments.