Encountering some Abbreviations in Modbus Specification. The name of file "MODBUS over serial line specification and implementation guide V1.02". Though I have Searched, but without any result.

what is fullname of VP (IDv Signal on page 30 in the file)? May be it a pin, but I don't konw its name.

what is fullname of CPT(on page 36 in the file)?

Can someone tell me full name?

Thank you very much.

Any answers will be appreciated.

 

I have version 1.01 of the spec, and it says the following:

VP - Positive 5...24 V DC Power Supply.

This is under the "Description for IDv" column on the right hand side of the table. I assume it means "Voltage Positive".

CPT - Serial Line Diagnostic Counters.

There is a table describing them on the previous page. I don't know how they got "CPT" from that.

 

some abbreviation which cann't explained Clearly confused the new learner.