The PV-143 is a single chip, four port Video4Linux supported capture card. Assuming that this is the only capture card installed in the computer it should be detected as /dev/video0. In order to access all ports you would need to specify sub devices:

Port 1: /dev/video0 Channel 0
Port 2: /dev/video0 Channel 1
Port 3: /dev/video0 Channel 2
Port 4: /dev/video0 Channel 3

All ports will need to have the same resolution and color palette. To verify the card is working run this command:

sudo xawtv -c /dev/video0

If this produces video, the card is functioning and if you still have an issue it's most likely a configuration issue with your software. Please contact your software vendor for assistance.