Smart Photoionization Detector Module PIDS3
User Manual
PIDS3 - User Manual (en) - 1.03.docx
Analytical Control Instruments GmbH, Volmerstraße 9A, 12489 Berlin, Germany, www.aci-berlin.com
Page 32 of 58
11.1
Message frame
Synchronization is implemented by embedding the user data into a transmission frame.
The device address is fixed to 0x00000000.
Message frame
0
1 … 8
9
10 ... (n - 10)
(n - 9)
(n -
8) … (n
- 1)
(n)
SOH ADDR 7 ... 0 SOT
DATA
ETX
CHK 7 … CHK 0
EOT
0x01
HEX
0x02
c SPACE + parameter
0x03
HEX
0x04
calculate checksum over this area
SOH
Start of Header (0x01)
ADDR
Device address
32 bit HEXSTRING (8 byte)
SOT
Start of Text (0x02)
DATA
C SPACE + parameter
ASCII or UTF-8 encoded
Command
Command part
Max. 32 byte, Min. 1 byte
SPACE
Space character (0x20)
Parameter
Parameter part
Max. 256 byte
ETX
End of text (0x03)
CHK
Checksum CRC32
32 bit HEXSTRING (8 byte)
EOT
End of transmission (0x04)
Example
Command
device?
Address [hex]
00000000
Checksum [hex]
969D9250
Bytes [hex]
01 3030303030303030 02 646576696365 20 3F 03 3936394439323530 04