Thermo Scientific 49i Instruction Manual page 311

Geysitech (Bayern-Hessen) Protocol
Geysitech Commands
The following are the different acceptable formats of the DA command
with Instrument Address 5:
<STX>DA<CR>
<STX>DA005<CR>
<STX>DA<SP><SP>5<ETX><BCC>
<STX>DA<ETX><BCC>
The data query string is valid and will be answered with data transmission
only if the command starts with <STX> which is followed by the characters
DA, and the <address> (if present) matches the Instrument Address, and the
command is terminated with either <CR> with no checksum or <ETX>
followed by the correct checksum <BCC>.
Sample Data Reply String in response to Data Query Command (DA):
In response to a valid data query command (DA) the instrument responds
in the following format:
<STX>MD02<SP><address><SP><measured
value1><SP><status><SP><SFKT><SP><address+1><SP><measured
value2><SP ><status><SP><SFKT><ETX><BCC>
The response uses the same command terminators as used by the received
command i.e. if the received command was terminated with a <CR> the
response is terminated with <CR> and if the command was terminated with
a <ETX><BCC> the response is terminated with<ETX> and the computed
checksum <BCC>.
The 02 after the MD indicates, that two measurements are present in the
reply string, (a 03 for three measurements and so on, this will also
determine the length of the reply string).
<address> is the Instrument Address. Each subsequent measurement
attached to the response will have the <address + X> where X keeps
incrementing by 1 for each measurement included.
<measured value> is the concentration value in currently selected gas units
represented as exponential representation with 4 characters mantissa and 2
characters exponent, each with sign.
Mantissa: sign and 4 digits. The decimal point is assumed to be after the
first digit and is not transmitted.
Thermo Fisher Scientific Model 49i Instruction Manual D-5