Servomex SERVOPRO Plasma - Page 25

Plasma Gas Analyzer
23 02001001A_9
The communication parameters of the analyzer are:
 Baud rate: 9600
 Parity bits: none
 Data bits: 8
 Stop bits: 1
The serial port on the rear of the analyzer (Figure 2 item 6) is an RS232 ± 5.5 V 9-way
'D' type connector.
Pin(s)
Use
1
Not used
2
Rx (to the analyzer)
3
Tx (from the analyzer)
4
Not used
5
0 V
6, 7, 8, 9
Not used
1
Figure 11 - RS232 CONNECTION PIN DETAILS
Standard RS-232 Interface - Transmission protocol
Note: see Appendix 4 for details of the transmission protocol for the Enhanced Interface
for use with External Valve Box
The different parameters are transmitted in the following order for the standard
interface:
ppm value sign, ppm value, TAB, flow, TAB, flow counts, TAB, cell counts TAB, status
and range, TAB, checksum, CR.
Each parameter is formatted as followed:
 PPM value sign: 1 byte equal to “+” or “-” in ASCII, depending on the
polarity of the ppm value;
 PPM value: 6 bytes in ASCII (3 digits before the dot and two after);
 Flow: 6 bytes in ASCII (3 digits before the dot and two after);
 Flow counts: 8 bytes in ASCII;
 Cell counts: 8 bytes in ASCII;
 Status and range: bitwise (logical on 8 bits);
1 2 3 4 5
6 7 8 9