PROFIBUS DP (COM465DP only)
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COM465IP-COM465DP_D00216_02_M_XXEN/03.2017
5.1.2 Correct control of the timing on the COM465DP using PROFIBUS commands is
necessary.
Due to the different times the various devices take to respond to the commands, it may occur that
responses from previous queries arrive between a query from the PROFIBUS DP master and the re-
lated response from the slave, (COM465DP). For this reason it is very important to compare the ID
numbers of the query and response.
5.1.3 The COM465DP communicates as "BMS master" with the PROFIBUS DP master
If you have given the COM465DP the BMS address 1, the device operates as a BMS master. In this way
it can be used as a master for all BMS systems. Along with querying alarm and operating messages,
it is also possible to issue switching commands and parameter settings directly.
5.1.4 Formats of the output and input data
The communication is to be considered from the point of view of the PROFIBUS DP. The PROFIBUS
DP master sends to the COM465DP (the PROFIBUS slave) a byte sequence, the output data.
As a response the PROFIBUS DP master receives back a byte sequence, the input data. The assign-
ment between input bytes and output bytes, that is between request and response, is defined via an
ID no. The PROFIBUS DP programmer must ensure the next ID no. is output as soon as the previous
request has been answered.
For the output data a length of 11 bytes is defined and for the input data a length of 10 bytes.
The PROFIBUS programmer is responsible for incrementing the ID no. in compli-
ance with system requirements. Incorrect control of the timing will result in the
misinterpretation of the responses (PROFIBUS input data)!
Take into account the time required to execute the related commands!
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