2 structure of a response sent from composer – INFICON Composer Gas Concentration Controller User Manual
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Composer Operating Manual
7.4.2 Structure of a Response Sent from Composer
Length Status Data Checksum
Length is one byte, and does not include the checksum or the length itself.
Status gives information about the command and the status of the instrument.
Bit 7 (MSB) is set if the command sent was successful. If it is clear, the
command was not successful, and the data is the error code. See
.
Bit 6 is set if there has been a power cycle since the last communication.
Bit 3 is set if there has been a change in the status of warnings in the
instrument. The state of the warnings can be found (along with the errors)
by doing an S 07 command. Bit 3 will remain set until an S 07 command has
been done.
Bit 2 is set if the concentration is steady.
Bit 1 is set if there has been a change in the measurement mode (amp
track, sweep, etc.) or a change in control state (control, stop, bypass, hold).
These states can be determined by the S 10 command. Bit 1 will remain set
until an S 10 command has read the current states.
Bit 0 is set if there has been a change in the status of errors in the
instrument. The specific error can be found by doing an S 07 command. Bit
0 will remain set until an S 07 command has read the error status.
Data are returned for some commands. The format of the data is determined by
the specific command. See
.
Checksum is a one byte sum of all the bytes in the command, not including the
length, the status byte or itself.