Modbus protocol support

CSWorks HMI and SCADA applications talk Modbus

Modbus is an application layer messaging protocol that provides client/server communication between devices connected on different types of buses and networks. Modbus has been the industry’s de-facto standard since 1979 when Modicon introduced the protocol in its PLCs. Modbus continues to enable millions of devices worldwide to communicate and it continues to grow in most industries.

CSWorks HMI: modbus data access
Access Modbus thermostat via adapter

Click on the image to enlarge it

Modbus is available as a serial protocol - Modbus RTU or Modbus ASCII, and as a network protocol - Modbus TCP. CSWorks supports Modbus TCP that allows CSWorks-powered applications to exchange data with Modbus TCP devices directly. If you want your CSWorks application to communicate to a Modbus RTU/ASCII device, you can use a Modbus RTU-TCP gateway appliance.

Modbus RTU-TCP gateway connects serial Modbus RTU/ASCII products to Ethernet LAN’s. The gateway acts a pure transparent connection between serial Modbus products and the Modbus TCP HMI/SCADA systems. A typical gateway can support multiple (up to 255) Modbus RTU/ASCII devices on the serial end. There is a well-established market for this kind of devices and a lot of models to choose from.

CSWorks installation package includes a sample that demonstrates how a CSWorks-based solution can be integrated with a room thermostat that supports serial Modbus protocol.

CSWorks supports all classic Modbus data types:

  • boolean (Discrete Output Coils and Discrete Input Contacts)
  • 8-bit and 16-bit integers (Analog Input Registers and Analog Output Holding Registers)
  • 32-bit integers (stored in a pair of Analog Input Registers or Analog Output Holding Registers)
  • 32-bit IEEE floating point values (stored in a pair of Analog Input Registers or Analog Output Holding Registers)

You do not need any additional software or middleware to make your CSWorks applications talk to Modbus devices. In CSWorks LiveData Service settings, specify the IP address of the Modbus device (or the gateway) and the Unit Id (sometimes called Slave Id) of the Modbus device, and specify which input/coil/register and address your data items should use.

Copyright © 2009-2016 CSWorks Inc. All rights reserved.