12.3 Manufacturer objects (0x2nnn) – Parameter access
For direct write/read access to inverter parameters via the SDO channel, a parameter
is addressed via index and sub-index. Index and sub-
index are used as follows for
accessing the inverter parameters:
Parameter number + 0x2000
required data set (0, 1 ... 4, 5, 6 ... 9)
The mapping of numeric data is always in integer or long data type. Values which
contain decimal places are extended accordingly:
(e.g. value 17.35 is transmitted as 1735)
12.3.1 Handling of data sets/cyclic writing of the parameters
Access to the parameter values is carried out on the basis of the parameter number
and the required data set.
There are parameters which only have one value (data set
0), as well as parameters which have four values (data sets 1...4). The latter are used
for the data set change-over of a parameter.
If parameters with four data values are set via data set = 0, all four data sets are set
to the same transmitted value. A read access with data set = 0 to such parameters is
only successful if all four data sets are set to the same value. If this is not the case an
error is reported.
The values are
entered automatically into the EEPROM on the controller. If values
are to be written cyclically, there must be no entry into the EEPROM, as it only has a
limited number of admissible writing cycles (about 1 million cycles). If the number of
admissible writing cycles is exceeded, the EEPROM is destroyed.
To avoid this, cyclically written data can be entered exclusively into the RAM without a
writing cycle taking place on the EEPROM. The data are volatile, i.e., they are lost on
power-off and have to be written again after power-on.
This mechanism is activated by the target data set being increased by five in the
specification of the data set.
Writing to a virtual data set in the RAM
04/13 CM-CAN ACU 75
To Next Page
Loading...
Need help?
General
