Modbus Master by Plasmionique Inc. Open-Source Modbus Master Library

  • Supports ASCII and RTU modes
  • Supports serial and TCP/IP networks
  • Multiple masters can share serial ports
  • Single master can communicate with multiple slaves
  • Includes Modbus tester example for verifying communication with slave devices
  • Includes documentation and example code
  • Download
The Plasmionique Modbus Master Library is an open-source add-on package for LabVIEW. It implements the Modbus Application Protocol Specification V1.1b3 for communicating with Modbus devices (slaves) over Asynchronous Serial or TCP/IP networks. Plasmionique Inc. developed it to replace NI’s Modbus V1.2.1 and provide an open source alternative to the Modbus API released by NI labs.

It supports RTU, ASCII, and TCP modes with the following function codes:

0x01 - Read Coils

0x02 - Read Discrete Inputs

0x03 - Read Holding Registers

0x04 - Read Input Registers

0x05 - Write Single Coil

0x06 - Write Single Register

0x07 - Read Exception Status

0x0F - Write Multiple Coils

0x10 - Write Multiple Registers

0x16 - Mask Write Register

0x17 - Read/Write Multiple Registers

0x2B/0x0E - Read Device Identification

The Plasmionique Modbus Master Library supports sharing a COM port across multiple Modbus sessions using VISA locks (10-second timeout).

It also supports sharing a Modbus session across multiple communication loops using a DVR as a mutex.

Support Information
This product is supported by the third-party provider and not by NI. For more information, contact Plasmionique at:


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