Starts the process of sequential writing of the database variable.
The method starts writing the database variable WID
sequentially, which causes the database variable to be "locked". The scheme of the sequential writing is:
method is used to populate the database variable with the values being written.
method is used to write the database variable to the station and "unlock" it.
A locked database variable will cause all reads to succeed, but the value is not actually read from the station (the result of the communication will be atrLock
). This protects the database variable against unintentional overwriting of successively written values by the LocalPutData
When the writing of own values is finished, the NetComposeEnd
method must be called to ensure that the database variable is written to the station and "unlocked". Failure to end the sequential write results in a permanent "lock" of the database variable!
The sequential write is cumulative, i.e. a double lock of a variable must be followed by a double unlock.