CAI 600-NDIR, Руководство пользователя

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Section 12 Model 601/601P/602/602P/603 NDIR Analyzer
California Analytical Model 600_NDIR_Series_v10.0 CE Operators Manual
Page 75 of 86
12.3.3. Data Description
Each command begins with STX (Start of Text) in the fist byte. The “don't care” byte can
be any ASCII character. Generally, a blank or an underscore (_) is used for readability
reasons. The four function bytes represent the AK command. A blank comes next, followed
by K and the channel number. The analyzer is a single-channel device, and because of
that the channel number is usually 0. For delimiting the command parameters from the
channel number, another blank follows. This may be followed by command parameters
with a variable length. Every command ends with the ETX (End of Text) character. The
error status byte in the acknowledgment command signals if internal errors in the analyzer
occurred. It is zero when no error appeared, and it is unequal zero when one or more
errors occurred. Every time a change in the errors happens the error status byte is
incremented by one, no matter if one or several errors disappear or are added. If it had the
value 10, it would be reset to 1. The error status byte does not indicate the real number of
errors. If the analyzer does not have errors, the error status byte contains the value 0.
In general, AK commands are subdivided into three classes:
•
Control commands (Sxxx)
•
Inquiry commands (Axxx)
•
Configuration commands (Exxx)
12.3.4. Error Handing
It might happen that an unknown instruction is sent, that the analyzer is busy with a
function which is not the desired one, or that an error occurred in the command
parameters. Table 1-4 summarizes all errors that can appear upon any master instruction.
Analyzers Acknowledgement Explanation
???? f1 Analyzer does not know the instruction sent.
xxxx
2
f BS Analyzer is busy with another function.
xxxx f SE Syntax error within command parameters or
incomplete command.
xxxx f NA Requested function or data are not available.
xxxx f DF Data error: The kind or number of given
parameters are not valid.
xxxx f OF Offline: Analyzer is offline, i.e. analyzer is in
local Mode. Only inquiry commands and SREM
(set analyzer in remote mode) are allowed.
Table 12-3 Acknowledgment response in case of error
1
f stands for the error status byte.
2
xxxx stands for the function code of the sent master command