Chuck Watson

I understand where you are coming from but I think we need different terms than client/server. The word server implies more power than a MODBUS slave has to offer. The...

To use your restaurant analogy, the counter is the slave interface (RS485/TCP) and the people behind the counter are the worker/slave threads in the remote device. The customer/master makes a...

This is an opensource project. If you want to customize the source code to do something unique, go ahead. That is one of the advantages of opensource. From the manual...

From the documentation: http://libmodbus.org/docs/v3.0.6/modbus_read_registers.html or http://libmodbus.org/docs/v3.1.4/modbus_read_registers.html The modbus_read_registers() function shall return the number of read registers if successful. Otherwise it shall return -1 and set errno. If not connected or...

Are you aware that most of this message is in an Asian script? Most people in this group can’t read the message and therefore can’t assist? If this was your...

I had the same issue recently. Below is a Hello World Modbus TCP server. Hope this helps. I have the following in my main() function. //Start Modbus slave/server thread pthread_t...

Code comment at the top: Hello World: Modbus slave function. Address node 3, data in registers 40001, 40002, and 40003 Of course no/limited error checking. IT IS a Hello World...

There is no security built into MODBUS or this library. If your slave device incorporates some kind of security process over MODBUS, that will be specific to that device. Read...

As a workaround, I converted my big numbers to JSON strings and then converted them back on the server.

I know this may sound crazy but, as a test, slow everything down. Adjust all your baud rates down to 19.2 or similar and adjust your timeouts up accordingly. What...