is it possible to connect hmi and advancedHMI to the same device?

[oqapsking]

hello

so i have a device connected to a HMI using rs485 port
when i connect my pc advancedHMI to it at the same time
it looks like it doesn`t work will
some times it reads it and other times it gives ( "read timeout" or "Checksum" )
if i disconnect the hmi then the advancedHMI works fine but not both at the same time
is it possible to connect them both at the same port at the same time ?

note : am using ModbusASCIICom
with thanks

[Archie]

Could this be a station address conflict? The Modbus driver does not allow you to set its own station address, only the target. I wonder if your existing HMI has the same station address (node number) as the AdvancedHMI application

[oqapsking]

Could this be a station address conflict? The Modbus driver does not allow you to set its own station address, only the target. I wonder if your existing HMI has the same station address (node number) as the AdvancedHMI application

Yeah i think it i station address problem
But the hmi doesn't allow me to change it

[oqapsking]

The hmi station address is 0
And it doesn't have the option to change it

[Archie]

It looks like the ModbusASCII driver is only capable of point to point and doesn't make use of the local node address.

After looking more into it, the Modbus protocol doesn't even accommodate it. There can only be one Modbus master in a network.

[oqapsking]

It is sad we can't fix that
Thanks man
I really appreciate your help