Festo Контроллер позиционирования CPX-CMAX - Manual (Page 307)

6. Parametrisation
6−17
Festo P.BE−CPX−CMA X−CONTROL−EN en 0908NH
Sequence
1. The PLC compiles the request data according to the funcĆ
tion number. The bytes in the data range that are not
used must also be transmitted. They should be set to 0.
2. The PLC transmits the data into the module parameters
byte 8 ... 61. When doing so it sets the PCB (byte 8) to 1.
The status byte should be set to 0.
3. The CMAX processes the request as soon as byte 61 has
been transmitted. If the CMAX has finished the procesĆ
sing, it enters the result in the status byte PSB (byte 9).
4. The PLC reads the data 8 ... 61 until it finds a value in the
status byte PSB (byte 9) that is not equal to 0.
5. If there is a result, the PLC must check whether the reĆ
quest was processed successfully (PSB = 1) or whether
an error was reported (PSB < 0).
Notes
ć Bytes 8...61 always have to be written. The request is only
processed by the CMAX after byte 61 has been transĆ
mitted.
ć If a result is retrieved before the request was requested,
PSB = 0 (request being processed).
ć When writing byte 8...61, make sure that PCB and PFB are
correctly allocated.
ć The contents of PSB are updated by the CMAX after every
write access of the PLC. The CMAX itself does not evaluate
the value written by the PLC. The value should be written
by the PLC with 0, so that the contents unequal to 0 are
reliably from the current request.
ć If a request is already being processed, new ones are
rejected and not processed (PSB = −4).