Teledyne 7120 - NDIR analyzer - Manual (Page 21)

Photometric Analyzer Installation 2
2-13 Teledyne Analytical Instruments
Figure 2-8: FET Series Resistance
2.3.4 RS-232 Port
The digital signal output is a standard RS-232 serial communications
port used to connect the analyzer to a computer, terminal, or other digital
device. It requires a standard 9-pin D connector.
Output: The data output is status information, in digital form, updated
every two seconds. Status is reported in the following order:
• The concentration in ppm or percent
• The range in use (00 = Range 1, 01 = Range 2, 10 = Range 3, 11
= Range 4)
• The span of the range (0-100 %, etc)
• Which alarms—if any—are disabled (AL–x DISABLED)
• Which alarms—if any—are tripped (AL–x ON).
Each status output is followed by a carriage return and line feed.
Input: The input functions using RS-232 that have been implemented
to date are described in Table 2-3.
Table 2-8: Commands via RS-232 Input
Command Description
as Immediately starts an autospan.
az Immediately starts an autozero.
rp Allows reprogramming of two System functions:
APPLICATION (gas use) and ALGORITHM (linearization).