R
I am new to Modbus protocol. I have read the spec and ported the stack and gotten basic functionality working (Master talking to a slave, reading and writing registers based on a map, handling exceptions).
I am trying to understand how to configure multiple slave-ids on an existing RS-485 network without having any duplicate slave-ids. Since modbus doesn't support response to broadcast packets, we cannot send a broadcast and ask for who has a particular slave-id...
My initial research tells me the following: (Please advice on better ways to configure slave-ids on devices without having any duplicate slave-ids).
a) Run a modbus scanner to identify used slave-ids on the network.
b) Configure slave-ids for the new devices to be added to the network (one at a time outside the RS-485 network). We cannot do this on the existing RS-485 network setup because all new devices will receive the same command to configure their slave-ids.
c) Once all slave-ids are configured, then add the devices to the existing RS-485 network.
Is this how EMS's do it? Are there better ways to handle this issue... as this involves ensuring manual configuration of slave-ids... any automated ways to do this?
Regards,
Rao
I am trying to understand how to configure multiple slave-ids on an existing RS-485 network without having any duplicate slave-ids. Since modbus doesn't support response to broadcast packets, we cannot send a broadcast and ask for who has a particular slave-id...
My initial research tells me the following: (Please advice on better ways to configure slave-ids on devices without having any duplicate slave-ids).
a) Run a modbus scanner to identify used slave-ids on the network.
b) Configure slave-ids for the new devices to be added to the network (one at a time outside the RS-485 network). We cannot do this on the existing RS-485 network setup because all new devices will receive the same command to configure their slave-ids.
c) Once all slave-ids are configured, then add the devices to the existing RS-485 network.
Is this how EMS's do it? Are there better ways to handle this issue... as this involves ensuring manual configuration of slave-ids... any automated ways to do this?
Regards,
Rao