Experimental Physics and
Industrial Control System

"Mark Rivers" <[email protected]> · Wed, 25 Nov 2009 12:34:51 -0600

Emma,

Once you get the communication with a single device working, you are
going to run into problems trying to communicate with multiple RS-485
devices through a single serial port.  The reason is that I am using the
asynInterposeInterface layer to add the RTU header with the slave
address.  But asyn only allows a single interposeInterface for each asyn
port, which restricts one to a single slave address.

Yves Lussignol from CEA has fixed this problem, by moving the slave
address management to layer 2 (asyn port driver) from layer 3 (interpose
interface).  He sent me a modified version of the driver with this fix
back in March 2009, but I have been remiss in not testing it and
releasing a new version of the driver.  It does change the syntax of the
drvModbusAsynConfigure command, so it will be a major release, i.e. 2-0.

I will try to get a new release out in the next couple of weeks.

Mark

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System