1 operating principle - example, Operating principle − example, Function library lenzecandsxdrv.lib – Lenze DDS Global Drive PLC Developer Studio User Manual
Page 10: Introduction, 1 operating principle − example, 2 candsx driver
2.2
CanDSx driver
Function library LenzeCanDSxDrv.lib
Introduction
2−2
L
LenzeCanDSxDrv.lib EN 1.2
2.2.1
Operating principle − example
Task
A user has implemented a functionality in his PLC which can be parameterised under user code
C3200/5. Code C3200 is automatically assigned to the index
dec
:
Index = 24575
dec
− code = 24575
dec
− 3200 = 21375
dec
The communication profile requires, however, that the functionality is parameterised under the index
4101
dec
/subindex 2.
Solution
Use the functions of function library LenzeCanDSxDrv.lib to redirect index 4101
dec
/subindex 2
within the PLC to code C3200/5 so that the communication profile need not be changed.
Operating principle
The operating system (as of V6.0) of Lenze PLCs includes a "mapping table" which allows to map
up to 256 codes on codes other than the automatically assigned codes within the PLC.
If a CAN telegram is received and the index is within the valid range, the system checks whether the
index is listed in the mapping table.
·
If the index is listed in the mapping table, the PLC accesses the new code assigned to the
index in the mapping table.
·
If the index is not listed in the mapping table, the PLC accesses the automatically assigned
code which results from the above formula.
SDO telegram
Index number
valid ?
CAN subindex
4101
yes
Index access:
4101/2
Code access:
C3200/5
Mapping table
CAN index
Lenze code
Lenze subcode
2
3200
5
4101
1
20000
0
3200
4
3000
0
SDO telegram
Index number
valid ?
CAN subindex
4101
yes
Index access:
21475/1
Lenze code = 24575 - Index = 24575 - 21475 = 3100
Code access =
C3100/1
Mapping table
CAN index
Lenze code
Lenze subcode
2
3200
5
4101
1
20000
0
3200
4
3000
0
Fig. 2−1
Redirection of indeces to codes