> For the complete documentation index, see [llms.txt](https://docs.yudash.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.yudash.com/yudash-iot-devices/zenyx-user-manual/zenyx-settings/modbus-rs485.md).

# Modbus RS485

Modbus/RS485 is a popular serial protocol to read various sensors. YuDash ZENYX is being used to read a variety of instruments, sensors and PLCs for various applications. LYNX provides easy to configure approach for reading field Modbus instruments. Following are the key information points required for a successful read of instrument through Modbus:

1. Baudrate
2. Data Bits, Parity and Stop Bit
3. Slave ID of instrument
4. Modbus register information to read:
   1. Modbus register numbers and types)
   2. Modbus register data types (Size: integer/float/real. Byte swapping information: LSB/MSB etc.)
5. Modbus register address.

## Modbus Register Mapping in YuDash ZENYX. <a href="#h.jt0n9eorg4hg_l" id="h.jt0n9eorg4hg_l"></a>

Refer to [LYNX Modbus RS485](/yudash-iot-devices/lynx-user-manual/lynx-settings/modbus-rs485.md) documentation for more details for Modbus settings.

Various Modbus topologies are covered in [Modbus protocol](/device-to-cloud-api/industrial-protocols/modbus.md) documentation.

## Modbus/RS485 interfacing example

YuDash ZENYX is connected with XY-MD02 temperature and humidity sensor through Modbus/RS485. Refer to [XY-MD02](/integration-guides/industrial-instruments/process-control/temp+humidity-xy-md02.md) integration guide for register mapping.&#x20;

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