Serial binding


Hope someone can help me out…
I want to controll a device with rs232 with a usb to seral converter.
When i operate the device i get feedback from the device in the log…
When i want to send a command i need to add a at the end…
somehow i cant get this to work… I tried every know variant: \r, \r, 0xD \0xD,,<CR>,…
no luck…

anybody got a hint on how to get this to work?

Hi Mathias

I don’t work with that binding. But I think you should provide some more details what kind of device you like to control, and what you have configured (item aso.), in order to get help.

And I think it is related to the specs of your device, what end character is needed.


Hi Stefan,

Thans for your quick reply…

The device i want to controll is an amplifier with rs232 controll…
I need to send “set master 50” to set the volume to 50

I have an Item “String Champ {serial=”/dev/ttyUSB0@19200"}"
When i change the volume on the amp my log shows that the string “champ” changes
So i do have connection with the amp.
but i cannot sent a command to the amp and i think it has to do with the at the end…


Hi Mathias

would be good to have the log from the binding in DEBUG mode. To see what the amp sends.
Maybe you would need a \n - but it is really difficult as I have no idea what it expects to receive.

Do you by chance talk about Audac AMP523MK2?

taken from the manual at audac website:

Set volume in zone 2 to -30dB
Command #|X001|F001|SV01|30|58ab|return
Answer #|F001|X001|SV01|+|ead6|return
Update #|ALL|X001|V01|30|aa95|return

where SV01 refers to Master Volume


  • The address of the AMP523 is fixed at X001.
  • The checksum is CRC-16 excluding the ‘#’. You can replace the checksum with ‘U’, this is
    always accepted as checksum.
    - return = 0x0d 0x0a

hope that helps


Hey Stefan,

This is the manual of the amp:

I need to send a “<CR>”

Thanks in advance!

So for the reference

Not sure if the changes got added to the serial binding, check this thread out.