NORD Drivesystems BU0270 User Manual
Page 40
Supplementary Manual EtherCAT for NORDAC SK 200E
40
Subject to technical amendments
BU 0270 GB
5.2.1.3 Setpoints and actual values (process values)
The meaning of the setpoint and actual values in the relevant frequency inverter is defined as follows:
Direction of transmission
Process value
SK 200E
SK 500E
Setpoint 1
P546 [-01]
P546
Setpoint 2
P546 [-02]
P547
Order to FI
Setpoint 3
P546 [-03]
P548
Actual value 1
P543 [-01]
P543
Actual value 2
P543 [-02]
P544
Status message from FI
Actual value 3
P543 [-03]
P545
Word:
PZD1
PZD2 PZD3 PZD4
Order STW SW1
SW2
SW3
Response ZSW
IW1
IW2
IW3
Bits
15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
The transfer of setpoint and actual values is carried out by three different methods, which will be explained below.
Percentage transfer
The process value is transferred as a whole number with a value range of -32768 to 32767 (8000 hex to 7FFF
hex). The value 16384 (4000 hex) is equal to 100%. The value -16384 (C000 hex) is equal to -100%.
For frequencies(setpoint frequency, actual frequency, frequency addition, actual frequency PID, …), the 100%
value corresponds to the FI parameter "Maximum Frequency" (P105) and for currents, this is the FI parameter
"Torque Current Limit" (P112) Frequencies and currents result from the following formulae.
16384
105
P
value
Frequency
×
=
16384
112
P
value
Current
×
=
Value = the 16Bit actual or setpoint value transmitted via EtherCAT
Binary transmission
Inputs and outputs as well as Digital In bits and Bus Out bits are evaluated for each bit.
Transmission of positions
For positions, a value range from +/- 50000.000 rotations is available. A motor rotation can be divided into a
maximum of 1000 steps. This scaling is independent of the encoder which is used.
The 32Bit value range is divided into a Low and a High word, so that 2 setpoint/actual values are required for
transmission. For this, it does not matter which of the 3 process data words is used.
Direction of transmission
Transmitted data (8 Byte)
1st word
2nd word
3rd word
4th word
Transmission to SK TU4-ECT
Control word
32Bit setpoint
Setpoint 3
Reception from the SK TU4-ECT Status word
Actual value 1 32Bit actual value
Depiction of 32Bit setpoint/actual values
Formula: Formation of 16Bit setpoint/actual value