Trace Oxygen Analyzer Installation
Teledyne Analytical Instruments 25
3.3.2.3 RS-232 PORT
The digital signal output is a standard, full duplex 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.
The output data 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 (HI, MED, LO)
• The span of the range (0-100 ppm, 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.
Three input functions using RS-232 have been implemented to
date. They are described in Table 3-5.
Table 3-5: Commands via RS-232 Input
Command Description
as<enter> Immediately starts an autospan.
az<enter> Immediately starts an autozero.
st<enter> Toggling input. Stops/Starts any
status message output from the
RS-232, until st<enter> is sent
again.
The RS-232 protocol allows some flexibility in its implementation.
Table 3-6 lists certain RS-232 values that are required by the 3000ZA
implementation.
Table 3-6: Required RS-232 Options
Parameter Setting
Baud 2400
Byte 8 bits