Use Function Code 0x06 for Single Holding Register Write

[h95332]

When writing to Holding Registers, I noticed that even when only a single register is written, the implementation still uses function code 0x10 (Write Multiple Registers).

According to the Modbus protocol, writing to a single Holding Register should typically use function code 0x06 (Write Single Register).

Would it be possible to modify or provide an option so that:

When only one register is being written, function code 0x06 is used instead of 0x10?

This could improve compatibility with devices that strictly expect 0x06 for single register writes.

[serhmarch]

Hello.

Would it be possible to modify or provide an option so that:
When only one register is being written, function code 0x06 is used instead of 0x10?

That's a very good point. I could add an option in the settings (for example, for the “Device” object) where users can choose how to write to the 16-bit register: using FC06 or FC16.

For now, I can suggest you to use SendMessage tool (menu Tools/SendMessage) to write a value:

[h95332]

Hello,

I am currently using the method you suggested, and through that I was able to confirm that the issue is related to the function code.

Thank you for your assistance.

[serhmarch]

I'll add the feature in TODO list, so it will be in the next release