Having trouble running a simple read register example about tokio-modbus

[uklotzde]

Maybe you need to switch the unit/slave id of the client context to 1 like you did in your Python code?

ctx.set_slave(Slave::from(1))

See also: trait SlaveContext

This is needed if the TCP device acts as a gateway. Otherwise the reserved unit id = 0xFF is used as the default for directly accessing the TCP device.

[uklotzde]

Once the slave/unit id is set it is used for all subsequent requests.

[glennpierce]

Thanks that was it.
I didn't replicate that bit from Python as it was not necessary to have it for the Python code. It must default to slave id 1.

Thanks

[uklotzde]

Feedback is always welcome.

[dave-andersen]

It would be really handy to have this documented in the TCP example, even if just a comment:
// If the device acts as a gateway, set the unit ID to 1:
// ctx.set_slave(Slave::from(1))

Took me quite a while to figure out why my Rust version wasn't working when porting a client from Go's goburrow/modbus, which also sets the unit ID as the Python library does and didn't need this configuration.