Circutor CVMk MODBUS communication protocol

Supported device types and versions 
Communication line configuration
Communication station configuration
I/O tag configuration
Literature
Changes and modifications
Document revisions

Supported device types and versions


MODBUS RTU MASTER supports data reading from the Circutor CVMk analyzers.

Communication line configuration


Communication station configuration



Station protocol parameters

There can be defined the following parameters:

Table 1

KeywordFull nameMeaningUnitDefault value
RC
Retry CountThe number of request retries when an error in communication occurs.-2
RT
Retry TimeoutDelay between request retries if an error in communication occurs.ms200 millisec.
WFT
Wait First TimeoutFirst waiting for the response after sending a request.ms100 millisec.
WT
Wait TimeoutDelay between the readings of a response until it is completed.ms100 millisec.
MWR
Max Wait RetryThe number of response reading retries until the response is completed.-15

String with protocol parameters is written according to this rule:

Key_word=value;Key_word=value;...

Example:

RC=1;RT=500;

If a keyword with a valid value has not been found in the initial string, the default value is used according to Table 1.

I/O tag configuration


I/O tags: Ai

Address – a number in the range of 0 to 65535 – number of MODBUS double register. It can be specified as a decimal number or a hexadecimal number with a hash at the beginning (e.g. #0ABC).

The values are read by 2 registers and interpreted as a 4-byte integer. The addresses of values are described in the literature about Circutor.

Literature


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Changes and modifications


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Document revisions


Communication protocols