Chino IRGMEG2 Series, Instructions Manual

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INST No. INE-479-P0 Software version 1.0
-7-
4.4 Data department
4.4.1 Data configuration
The configuration of the data differs by the function code.
The demanded data from the master is configured of the code number (Relative number that
calculates it from [4.4.2 Reference No.]) and data number etc. to the reading and writing of the
object data. The answer from the slave is configured of the demanded data etc.
The basis data of MODBUS is all the integers of 16 bits and the existence or nonexistence of the
mark is prescribed at each data.
4.4.2 Reference No.
"The reference number" of the list shown below is assigned to the data inside IRMA series infrared
multiple-constituents analyzer detector unit Model for IRMA
.
This number is required to the reading and writing of data.
It is classified like the list shown below by the kind of data.
The number appointment in the message is "Relative number" that corresponds to each reference
number.
Kind of data Reference number Relative number
Digital setting value 1 to 10000 Reference number: 1
Digital input data 10001 to 20000 Reference number: 10001
Analog input data 30001 to 40000 Reference number: 30001
Analog setting value 40001 to 50000 Reference number: 40001
4.5 Error check
The error check of the communication frame uses CRC-16.
4.5.1 Calculation of CRC-16
The communication method of the CRC system divides the information that should be sent with the
generation polynomial expression and add the remainder behind information.
The generation polynomial expression is as follows.
Calculate the data from the slave address to last data with the following procedure.
1) Initialize the data of CRC-16 (It makes X): (=FFFFH)
2) Exclusive OR of data 1 and X: (E
X
-OR) → X
3) Shift X to the right 1 bit → X
4) If a carry comes out, take A001H and Ex-OR. Move to 5) if a carry does not come out.
5) Repeat the above 3) to 4) until it shifts 8 times.
6) Next data and X of Ex-OR
→ X
7) With from 3) to 5) same.
8) Repeats it to the last data.
9) The message is made in order to the upper class from the subordinate class of calculated 16 bits
data (X).
The relative number of the measured value (temperature data) of "reference number
30011" becomes "10".
4. MODBUS protocol-Message
The data of an error check becomes , because CRC-16 becomes
1241H in the case that data is .
02H 07H
41H 12H
R e m a r k s
1 + X 2 + X 15 + X 16
R e m a r k s