Digium board does not hang up calls

I have a 4 FXO card installed on an asterisk server, this ports are connected to a Siemens PBX and calls are being placed through the asterisk, but when the user hangs up, the board does not hang up the call and the channel stays occupied. How can I configure the board to recognize the user hanging up?

Check out the Spanish site www.asterisk-es.org. Do a search for “Deteccion de colgado” or something similar. You should find a patch that needs to be installed in order to detect the polarity switch that signals a hangup. This is an issue here in Spain.