USB CDC and Modbus

[rwskinner]

I'm using the CCS Modbus RTU slave lib on one of the RS232 ports and using CDC for other messages to the PC, mainly debugging.

The only time that the USB CDC enumerates properly is if there is not modbus traffic. I'm sure this is because the traffic is causing delays and the usb_task does not get serviced in the required time frame.

Once it enumerates everything works fine but if you disconnect the usb and reconnected it, it again will not enumerate until you stop all traffic or cycle the power.

usb_task is being called in a tight loop in my main however it is still a problem.

Should I try to add it somewhere in the CCS modbus lib such as the timeout isr or the serial receive isr so it's called often enough?

Any suggestions?

Richard

[rwskinner]

Anyone?