Single ParameterizationΒΆ
The single parameterization services can be used to read or write parameters during runtime of device without the need of triggering a new parameterization process.
For indexes used for single parameterization services see parameter lists in section MODBUS TCP registers of this document.
The read and write parameterization services are explained below, for each module (CI52x-MODTCP and connected expansion modules) a different section for read and write is defined see chapter MODBUS TCP registers in this document). Both services are using the following data structure:
The length of the read / write service depends on the count of parameters that should be transferred (length = 4+ count*8).
Reading of Single Parameters
The read single parameterization works in two steps:
Writing of a request list containing the indexes that should be read using the structure explained above.
Only CNT and PARA_IDX has to be set.
Up to 5 parameters can be requested with one telegram.
The length of the write service depends on the count of parameters that should be transferred (length = 4+ count*8).
Reading of the parameters list with the same length then the previous write request.
If the internal reading process inside the CI52x-MODTCP device is done the data will be read out.
If the internal reading process inside the CI52x-MODTCP device is not yet finished the read service will be rejected with MODBUS TCP exception code 6 (device busy).
Writing of Single Parameters
For writing of single parameters only one step is necessary, the parameters are transferred with one write request using the structure described above.
The length of the write service depends on the count of parameters that should be transferred (length = 4+ count*8).
In case of write of single parameters the following values have to be set:
CNT: number of parameters to be set
And for each parameter:
Parameter index
Parameter length
New parameter value
Written single parameters are not stored volatile and not stored nonvolatile. That means after a bus reconnection or power cycle the written parameters will be discarded.