Users manual
Appendix A
Revision #:
A
Date:
07-14-15
Page
7
of
58
4
Proprietary Sentence Format:
3 bytes
3 bytes
Field
Description
$
Start-of-Sentence marker
P
Proprietary sentence identifier
<maker ID>
3-byte fixed length.
GT-87’s maker ID is “ERD” meaning eRide.
<sentence type>
Indicates the type of sentence.
<data field>
Variable or fixed-length fields preceded by delimiter
“,”(comma).
(Layout is maker-definable.)
<checksum field>
8 bits data between “$” and “*”(excluding “$” and “*”) are
XORed, and the resultant value is converted to 2 bytes of
hexadecimal letters. Note that two hexadecimal letters must be
preceded by “*”, and delimiter “,” is not required before
*<checksum>.
All output sentences have checksum.
For input sentences, the resultant value is checked and if it is
not correct, the sentence is treated invalid.
<CR><LF>
End-of-Sentence marker
$ P <maker ID> <sentence type> ,
<data field> … *<checksum field> <CR> <LF>
