Joining transition

This function block is used to end a fork in a sequence control and join two simultaneous chains.

The function block has the inputs SB, TI, TI1 and the output TO. If both Steps connected to TI and TI1 have a token and the transition condition is met, i.e. SB is HIGH, a token can pass to the Step connected to the output TO. The two incoming token are merged to a single outgoing token.


TI, TI1 and TO have to be connected. Otherwise the download to the target system will be disrupted with an error message.

For general information about sequence functions and its realization see introduction.


Name I/O Type(s) Function
TI I TOTRANS Sequence input
TI1 I TOTRANS Sequence input
SB I BIT Passing condition
TO O TOSTEP Sequence output


If the transition is not connected properly, the symbol will be depicted red in runmode.


The function block Splitting transition can be used for splitting into two simultaneous chains.