ACOEM Met One Instruments GAS-1060, Руководство пользователя

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Parts List Page 157
Appendix C. Bayern-Hessen Protocol
The Serinus implements a limited subset of the Bayern-Hessen Network protocol. Only the ability to
set the instrument calibration state (measure, span or zero) and read the gas concentrations are
supported.
C.1 Command Format
<STX><text><ETX>< bcc1><bcc2>
Where:
<STX> ASCII Start of Text = 0x02 hex.
<Text> ASCII text maximum length of 160 characters.
<ETX> ASCII End of Text = 0x03 hex.
<bcc1> ASCII representation of block check value MSB. (That is, the character
“3” for 3, the character “F” for 15, etc.)
<bcc2> ASCII representation of block check value LSB.
The block check algorithm begins with 0 and exclusive-OR’s each ASCII character from <STX> to
<ETX> inclusive. This block check value is converted to ASCII format and sent after the <ETX>
character.
Examples
This is an example of a valid Bayern-Hessen data request for an instrument that has a Serial ID of 97
(Serial ID assigned in the
Main Menu

Communications Menu

Serial Communication Menu ):
<STX>DA097<EXT>3A
The block check calculation is best shown by the following example:
Table 20 – Bayern-Hessen Data
Character Hex Value Binary Block Check
<STX> 02 0000 0010 0000 0010
D 44 0100 0100 0100 0110
A 41 0100 0001 0000 0111
0 30 0011 0000 0011 0111
9 39 0011 1001 0000 1110
7 37 0011 0111 0011 1001
<ETX> 03 0000 0011 0011 1010