ROTRONIC MBW 973 - Manual (Page 35)

Command Syntax 31
Even if the command is not a request for data, but rather is a command to change a setpoint
or parameter, the 973 still responds with a carriage return line feed combination. The
following turns on the pump (if your unit is so equipped). Notice that no data is returned, but
the 973 sends a
C
R
L
F
acknowledgement that the command was valid.
Pump.on = 1 C
R
(sent by the computer to the 973)
C
R
L
F
(the acknowledgement from the 973)
However, if the command is unrecognized, the 973 does not respond. See the example.
Abcdef? C
R
(invalid command sent from the computer)
(no response from the 973)
Leading and Trailing Spaces
The 973 ignores leading and trailing spaces. It also ignores spaces before and after equal
signs and question marks. For example, each of the following commands is perfectly valid.
Dp? C
R
Dp ? C
R
Pump.on=1 C
R
Pump.on = 1 C
R
However, the following commands are invalid since spaces are embedded within the
keywords.
D p? C
R
Pu mp.on=1 C
R
Case Sensitivity
All commands are insensitive to case. In other words, it does not matter if the command is
sent in upper case letters, lower case letters, or as some combination of the two. For
example, the commands DP?, Dp?, dP?, and dp? are identical to the 973 and will return the
measured dew point value.
Numeric Values
All numeric data sent to or received from the 973 is done so in either standard or scientific
notation. Sending a number as 12.34 is the same as sending it as 1234e-2 or as 1.234e1.
Depending on the value of numeric responses the 973 sends out, it may send the numbers in
either standard or scientific notation.
Numeric data is never appended with text of any kind. In other words, if requesting a
temperature related value, only the numeric portion of the value is sent. The units are
assumed but never sent.
The following table lists the units that numeric data adheres to, regardless of the units
selection on the touch screen display or set via the RS-232. In other words, when you
change units (even if you changed them via RS-232), you affect only what is seen on the
display. All numeric values retrieved from the RS-232 will always be in the following units.
Also, when sending data of any kind, do so in these same units.