NDIR
Gas
Analyzer
Appendix
Teledyne Analytical Instruments., - Rev. 3
73
•
The code section of any message is always 3 characters in
length. The codes are case sensitive. They must be sent exactly
as follows:
The first character is lower case
The second and third are upper case
•
If the decimal value (eDV) for the instrument is -1, then the
numeric value for the gas concentration is multiplied by 10 in
the instrument display.
For
example:
(e1L) returns (e ) and the display reads +5000.
•
There are 5 types of code. Each type starts with a type
identifier character followed by 2 characters that select the
specific message within that type. The 5 types of code are: "e",
"s", "c", "m", and "a".
•
"e" type codes:
Messages containing "e" type codes cause the instrument to
reply (emit) with information that was requested by the code. It
does not change the operation of the instrument.
Example: From user:
(eAE)
Back from instrument:
(eAE enabled)
•
"s" type codes:
Messages containing "s" type codes cause the instrument to
change a setpoint to the value sent with the code.
If a setpoint code is properly executed, the return message
will be the code as interpreted by the instrument.
These setpoints are normally changed through the buttons
on the instrument's front panel. To prevent a conflict
between the front panel entry and the serial port entry, the
code which locks the front panel must be sent before a type
"s" code will be obeyed. The panel unlocking code should
be sent when finished so normal operation of the front
panel will resume.
If setpoint codes are sent without locking the panel, a
message inside the start/stop characters will be returned
with the original 3 character code followed by the text
string "
need_panel_lock
".
If a setpoint code containing an inappropriate value is sent,
one of several error codes will be returned.
All setpoints are stored in 16 bit registers so all setpoint
values must be less than 65,000 and must be positive.