Sequence Format - shelyak SENTINEL PF0007 Guide Utilisateur

Sequence format

Protocole is the following: PC sends a request sequence and Sentinel replies with a sequence.
Sentinel always replies to PC's request and never send data by itself.
A sequence is made of a number of bytes. Here M bytes.
First byte is always 0x1D (beginning of sequence); second byte is the number of byte, ie number of
data plus 1 for checksum which comes last.
Valeur
Octet
Sequence
N°
Function
Data0 byte define the request details; Data1 to DataN bytes are optional parameters for that
specific request.
Minimum sequence size is M=4.
Maximal sequence size is M=24.
Checksum is the sum of bytes from sequence n° 1 to (M-1).
Here is an exemple of a simple sequence with request 0x1A (=Data0):
Byte value
True value
Seq. N°
Function
Request sequenc 0x1A means sending 4 bytes through serial port: 0x1D,0x02,0x1A et 0x39.
Sentinel will respond with a 15 bytes sequence:
Byte value
True value
Seq N°
Byte value
True value
Seq N°
Colors represents a data grouping to form long variable: Byte (1 byte), word16 (2 bytes),
LongWord32 (4 bytes), LongWord24 (3 bytes).
Sentinel – User Guide (Français / English) – DC0011C
0x1D N+2
1
Beginning Nb+1
0x1D
0x1D
1
Beginning
0x1F N+2 Data0 Data1 Data2 Data3 Data4 Data5
0x1F 0x0F
1 2
Data6 Data7 Data8 Data9 Data10 Data11 Check Sum
0x3C 0x00
9 10
Data0 Data1 ... DataN Check Sum
2 3
Request Param1 ... ParamN Check Sum
N+2 Data0
0x02 0x1A
2 3
Nb+1 Request
0x02 0x04
3 4
0x00 0x04
11 12
4 ... M-1
Check Sum
0x39
4
Check Sum
0x00 0x00 0x00
5 6
0x10 0x30
12 14
M
0x00
7 8
0x00
15
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