The GigE Vision™ Control Protocol (GVCP) is an application protocol relying on the UDP transport layer protocol. Because UDP is a connectionless protocol, a recovery mechanism has been defined to detect that one of the two participants has been detached without closing the control channel before. A heartbeat message is used to achieve this.
In the default operation mode, these heartbeat messages are exchanged with a user selectable frequency ("Setting → Base → Camera → GenICam → Device Control → Device Link Heartbeat Timeout"; orange box in Figure 1). As a result, during this interval a certain register (GevCCP = Control Channel Privilege) is read several times from the device to reset the heartbeat timer interval in order to ensure the control channel stays open.
If the heartbeat bit is set to disable ("Device Link Heartbeat Mode = On"; red box in Figure 1), the transport layer lib will stop reading the GevCCP register periodically. To disable the heartbeat makes sense for at least two scenarios:
- while debugging a program and
- in Triggered line scan acquisition with pausing trigger signals.
In both scenarios, one participant pauses the connection on purpose.
If the heartbeat disable bit is reset again, the transport layer lib will start reading the CCP register periodically again.
