Data transfer to the PLC
7.3 Functional sequences/description of functions
3WL/3VL circuit breakers with communication capability - PROFIBUS
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System Manual, 03/2011, A5E01051353-02
UNSYNC
SYNC mode of the addressed DP slaves is revoked with the control command UNSYNC.
The DP slave is then involved again in cyclic data transfer, that is, the data sent by the DP
master is switched immediately to the outputs.
FREEZE
The control command FREEZE enables the user to "freeze" the input data of DP slaves. If a
FREEZE command is sent to a group of DP slaves, all these DP slaves simultaneously
freeze the signals currently active at their inputs. These can then be read by the DP master.
The input data on the DP slaves is not updated until after receipt of a new FREEZE
command.
UNFREEZE
The control command UNFREEZE revokes FREEZE mode of the addressed DP slaves so
that these return to cyclic data transfer with the DP master. The input data is immediately
updated by the DP slave and can then be immediately read by the DP master.
Please note that after a complete restart or a restart, a DP slave does not change to SYNC
mode or FREEZE mode until it has received the first SYNC or FREEZE commands from the
DP master.
7.3.3
Time synchronization
General
To achieve a reliable time of day in conjunction with all other circuit breakers, the clock in
every device must be regularly synchronized with the other switches to the correct time.
Step 1 Updating the time of day
Load the current time into every circuit breaker from the PLC. First, data set 68 with the
current system time must be sent to all circuit breakers via the acyclic services of the DPV1
channel.
(See Chapter Write data sets (Page 159)).
Step 2 Sync frame
Shortly before the half hour (e.g. 14:29:50), send a SYNC command to the affected SYNC
group.
From now on, all control commands until the next SYNC command or the next UNSYNC
command will be delayed.
(See Chapter Sync/Unsync/Freeze/Unfreeze (Page 161))