cups cupsBackChannelRead

[velupillai]

hello,

yesterday, my port monitor for usb backend (mandriva 2007 + cups 1.3.5) run successfully.
Today i tried to run it for serial backend (with the same machine and the same configuration), cupsBackChannelRead failed and return -1.

Then i tried it on another machine (mandriva 2007 + cups 1.2.10) for usb backend and serial backend. cups don't execute my port monitor for both backends. it seems to ignore the key word cupsPortMonitor and do not start the program defined as port monitor.

which is the good configuration (Cups, cups serial, cups driver ... version) to run port monitors.
why did it not work for serial backend?

Thanks in advance.