22 S1A10386 10/2009
PROFIBUS DP mapping
PKW aperiodic service
The PKW service, consisting of PKE, R/W, R/W/N and PWE, enables aperiodic access to Altivar312 parameters in read and write mode.

Output PKWs

PKE

Parameter logic address

R/W

0: No request
1: Read
2: Write
One-off read and write requests can be triggered continuously while R/W equals 1 or 2.
Note:
Values other than 0, 1 and 2 should not be used.

PWE

If write: Value to be written

Input PKWs

PKE

Copies the output PKE value

R/W/N

0: No request
1: Correct read operation
2: Correct write operation
7: Read or write error

PWE

• If correct read operation: Parameter value. This can be limited by the drive if the maximum value is exceeded by the write operation.
• If correct write operation: Value of the write PWE
• If there is an error:
0: Incorrect address
1: Write operation refused
Note:
The parameters in the output PZDs should not be changed by the PKW service.
Parameters linked to output PZDs should not be changed by the PKW service.
Example: The speed target and the frequency target.