3 writing a parameter – NORD Drivesystems BU0220 User Manual
Page 75
BU 0220 GB-0912
Subject to technical amendments
75
7.3.3
Writing a parameter
When transferring parameter orders, it must be taken into account that the slave does not immediately respond
to orders in the parameter channel of the master telegram, but a positive response can be delayed by one or
more communication cycles. The master must therefore repeat the required order until the corresponding slave
response is received. PPO type 1 or PPO type 2 must be selected (Section 7.2).
The parameter (P102) "run-up time" (PNU = 102
dec
/ 66
hex
) is to be set to the value 10sec in parameter set 3. (Only
the PKW channel is evaluated). (Only the PKW channel is evaluated.)
As the acceleration time has a frequency-internal resolution of 0.01sec, a parameter value of 10 / 0.01 = 1000
(3E8
hex
) must be transferred for 2 sec.
Procedure:
1) Specify order label ("Change parameter value (array word)"
→ AK = 7)
2) Select parameter (P 102
dec
+ 1000 = P 1102 = P 44E
hex
)
3) Select parameter set 3 (IND = 02)
4) Set parameter value (1000
dec
/ 3E8
hex
)
5) Check response telegram (positive for array word = 4)
The telegram is composed as follows in hexadecimal notation:
word
1
2
3
4
Byte
0
1
2
3
4
5
6
7
Designation
PKE
IND
PWE
PWE
Value
74
4E
02
00
00
00
03
E8
When the order has been fully implemented by the inverter, it responds with (hexadecimal):
word
1
2
3
4
Byte
3
4
5
6
7
8
9
10
Designation
PKE
IND
PWE
PWE
Value
44
4E
02
00
00
00
03
E8
ATTENTION
If parameter changes are made (i.e. requests via the PKW area by the control master), care
must be taken that the maximum number of permissible writing cycles to the frequency
inverter EEPROM (100,000 cycles) is not exceeded. I.e. continuous cyclical writing must be
prevented.
For certain applications it is sufficient if the values are only saved in the RAM memory of the
frequency inverter. The corresponding setting is made via parameter (P560) "Save in
EEPROM".