Festo Кабели и принадлежности - Manual (Page 109)

5. Parameter channel
5−9
Festo P.BE−SPC200−COM−PDP−E N en 0901c
Please note
Observe the following when modifying parameters:
An I/O control signal, which is to refer to a modified paraĆ
meter, may only be transmitted if the reply identifier ParaĆ
meter value transmitted" has been received for the relĆ
evant parameter and, if applicable, for the index.
If, e.g. a position value in a position register is to be modified
and if a movement is then to be made to this position, the
positioning command must not be given until the SPC200 has
completed and confirmed the modification of the position
register.
The SPC200 continues to provide the reply until the master
has formulated a new task. With reply telegrams to the tasks
Request parameter value (array)," the SPC200 always
replies in cyclic repetition with the updated parameter value.
A write task, even with cyclic repetition of the same task, will
only be carried out once by the SPC200. If the same write
task is to be carried out by the SPC200 several times one
after the other, an empty task (AK = 0) must be sent when a
positive reply identifier is received.
The parameters are transmitted cyclically with each I/O upĆ
date of the master. The reaction of the SPC200 to a new task
cannot however take place in the same bus cycle. When the
SPC200 has recognized the new task, it sends the reply to the
last task.
When the new task is recognized, it sends the reply identifier
0 (no reply), until it can provide the reply.