Ecotech Serinus 44 - Appendix C. Bayern-Hassen Protocol; Bayern-Hassen Network Command Format

Serinus 44 User Manual 3.0
Page 168
Appendix C. Bayern-Hassen Protocol
All Bayern-Hassen Network commands follow the command format as specified in this section.
Bayern-Hassen Network Command Format
<STX><text><ETX>< bcc1><bcc2>
Where:
<STX> = ASCII Start of Transmission = 0x02 hex
<Text> = ASCII text maximum length of 120 characters
<ETX> = ASCII end of transmission = 0x03 hex
<bcc1> = ASCII representation of block check value MSB
<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-Hassen data request for an instrument that has an ID of 97:
<STX>DA097<EXT>3A
The block check calculation is best shown by the following example:
Table 13 – Bayern-Hassen 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
The binary value 0011 1010 corresponds to the hex value 3A. This value in ASCII forms the last two
characters of the data request message.
Note: The I.D. of 97 is sent as the sequence 097. All I.D. strings must have three digits and you should
always pad with ASCII zero characters.