Device ID 0 is not accepted

[ondrej1024]

I noticed that it is not possible to enter 0 in the Device ID field. It is corrected automatically to 1.

However, addressing a Device ID (or unit identifier) of 0 is allowed in the Modbus standard. For the Modbus TCP protocol this is typically used for communication via a Gateway where Device IDs 1 to 247 are forwarded to connected RTU devices, but Device ID 0 addresses the gateway itself.

For Modbus RTU the Device ID 0 is the broadcast address, but it is used only for write operations because the slave does not respond to broadcast requests.

So it would be great to have the possibility to set a Device ID of 0.

Thanks

[sanny32]

Hello @ondrej1024. Thank you for your attention to details. I will fix this at next release.

[ondrej1024]

Sounds great, thanks for your work

[wltue]

I want to thank you too. Amazing utility!