BECKHOFF AX2000 PROFIBUS DP communication profile - Manual (Page 48)

6.1.10 Writing a parameter (via parameter channel PKW)
Parameter v_max is used as an example to show how control parameters are transmitted from the
master to the AX2000/2500.
Parameter number: 1816 111 0001 1000
Parameter value: 350000 µm/s 0000 0000 0000 0101 0101 0111 0011 0000
Byte 1 2 3 4 5 6 7 8
0011 0111 0001 1000 0000 0100 0000 0000 0000 0000 0000 0101 0101 0111 0011 0000
PKE IND PWE
Note: after an error has occurred in parameter transmission (AK = 7), a “Zero telegram” should be
transmitted, i.e. the first 8 bytes of the transmit telegram from the PLC should be kept at 0, until the
AX2000/2500 has responded with a zero telegram.
6.1.11 Reading actual values
Cyclical actual value request
This PKW task switches on the reading of an actual value. The actual value will now be transmitted
with each cyclical telegram – until a new PKW task is presented.
Telegram layout:
Request Response
PKE/AK 1 2
PKE/PNU Parameter number of the actual values as transmitted
IND 0 = read 0
PWE no significance actual value
48 PROFIBUS for AX2000/2500
Appendix
12/05
BECKHOFF