Synchronization

sync

sync()

Synchronizes the interpreter with the associated NC-channel. The sync()-command blocks until all pending NC-commands are completed, i.e. until the job-queue of the NC-channel is empty. This command replaces the former @714-command. Oftentimes, the sync()-command is combined with a preceeding M-function of type handshake. Then, the sync()-command will block until the M-function is acknowledged by the PLC.

wait

wait()

Waits for a GoAhead-signal from the PLC. The wait()-command blocks until this signal is received. This command replaces the former @717-command. Compared to a combination of an M-function and sync(), this kind of synchronization does not result in an empty job queue. Notably, an empty job queue forces the machine to halt.

The GoAhead-signal may be send from the PLC before the associated wait()-function is called. In this case the wait()-function does not block.