old joke....

Yes, I get that, but perhaps the protocol or something else has an error that relates to baud rate in use, and the way to check is to run different ones to see if it changes something.

I'm programming a Smart Home system. but controlling a washing, drying or dishwasher is a challenge. These are not equipped with KNX or RS485 or do not start automatically by switching with a contactor. Most suppliers work with Home-Connect and their own connectivity. I am also looking to do this via Unitronics, but have not yet found anything on the internet in terms of communication protocol and which setting can control a drying machine, for example. Anyone wtih experience?

I had the same problem few days ago, since I wanted to write date as string for future database use. Just like Joe said, just import that function and call it. I made both strings 15 in lenght. BR E.P.

No worries.  At this point I am happy to be questioned on anything The link is terminated correctly.  The baud rate I'm using is 115.2kbaud. Just to clarify, for debugging purposes and to try to understand the Modbus errors, I'm not even connected to a slave device right now.  I'm just transmitting to a terminal app on a PC.  I have not seen any communication errors at all - by no errors I mean no bit or byte errors.  All commands that are transmitted are received at the terminal properly formatted and with correct CRC. The issue appears to be when the Modbus Master determines there is an error (either because there is no response or because the next transmission happened too quickly before the previous one has timed out - within 500ms).  So , it's not so much a comms issue, but more a protocol issue I'm dealing with.   I've been discussing with Unitronics support, but I have to question their responses.  They are claiming that the only time there is a 3 second suspension by the Master, is when a transaction generates a -2 error code.  However, when I try to send three transactions in a row, with a 1 second delay between each, it does not work.  The first command times out (as expected since I am not trying to respond) and generates an error code -11 as expected.  However, the second command does not transmit at all and generates an error code -2 even after waiting a full second.  Since the 1 second delay between 1st and 2nd commands was not enough, this leads me to believe that the -11 timeout error also caused this 3 second suspension in the first command.  If I increase the inter-command delay to 3.5 seconds it works, which again leads me to believe the 3 second suspension is being generated by the timeout even though Unitronics support says it does not.   I know from the documentation that the -2 error does cause the 3 second suspension (maybe others too), but what they have been unable to tell me is what actually causes a -2 error to occur?  What is the condition that generates it?