STOBER
10 | More about MC6 and AS6?
05/2018 | ID 442461.04
69
10.2.2.4
Master cycle time is a multiple of the slave cycle time
If the master cycle time is a multiple of the slave cycle time, check the following condition:
Sync Offset
Master
+ Shift Time
Slave
- PLL-phase offset
drive controller
< Slave- cycle time
drive controller
§
If this condition is met, no special settings are required.
§
If the condition is not met, configure the Shift Time
Slave
so that the condition is met. The Sync
0 pulse has to occur before the drive controller uses the received data.
Specify the shift time for each drive controller in AutomationControlSuite; define the PLL-phase
offset in DriveControlSuite in the A292 parameter. These two values should be set the same for
each drive controller.
Information
STOBER recommends setting the data transmissions (I/O) to task begin in the EtherCAT
configuration. This results in one motion cycle being lost as dead time, however you will get
significantly less jitter. This leads to better synchronization between the MC6 and the drives.
10.2.2.5
EtherCAT synchronization – parameterization examples
EtherCAT cycle time: 4 ms, drive controller cycle time: 1 ms
Example 1
Master shift time = 800 μs (20% of 4 ms)
Slave shift time= -400 μs
PLL-phase offset = -200 μs
Example 2
Master shift time = 800 μs (20% = default)
Slave shift time = 0 μs (default)
PLL-phase offset = -100 μs
10.2.3
Persistent variables
Alarms such as faults or messages are automatically saved in non-volatile storage on drive D of
the MC6 by the Alarm Manager. The Persistence Manager or the NOVRAM of the MC6 are
available as non-volatile data memory in order to save running-time meters, part counters or
other data.
Persistence Manager
If you would like to manage a large amount of non-volatile data easily, you can use the
Persistence Manager module.
Configure the module so that the data can be stored on drive D, which is provided for this
purpose. In addition, assign the variables in the global variable list to the channel of the
Persistence Manager.
The amount of data is limited only by the space available on the D partition of the CFast card.
You can reduce the risk of losing data by using two redundant files.