Talk to a Zelio Logic Relay with an Ethernet/Modbus module.


Thread Starter

Miguel Hidalgo

I want to talk to a Zelio Logic Relay with the SR3-NET01BD Ethernet/Modbus module using the PC and VB.NET to control and know the status of a network of Zelios controlling Air Conditioning Units and pumps. Currently the Zelios are independent units automating and controlling the AC Units and pumps. We want to interconnecting to a Master (PC) or web app. so they can be monitored and control remotely through TCP/IP. The only info I found about the Zelios is the Functions 3, 6, 16 and 43 for a Twido to communicate with them. We need control as masters!

Any idea, sample code, etc.

Thank You! from Nicaragua

Miguel Hidalgo
Modbus Function code 16 writes to a slave.


6.12 16 (0x10) Write Multiple registers

This function code is used to write a block of contiguous registers (1 to 123 registers) in a remote device.

The requested written values are specified in the request data field. Data is packed as two bytes per register.

The normal response returns the function code, starting address, and quantity of registers written.

The Zelio devices are Modbus Slaves. Your PC is the Modbus master.

If you don't want to write your own HMI program that acts as the Modbus Master, there are literally hundreds of HMI/SCADA/DAQ PC software programs with (sometimes optional) Modbus drivers whose purpose in life is to read data from and write data to field devices.

Many of these HMI/SCADA/DAQ programs function as an OPC client, which uses a separate, (usually licensed) OPC server program to do the Modbus communications with the field device.

You might start with Zelio's manufacturer or try our best friend, Google. LabView finds wide use in academic settings.