Campbell Scientific SDM-SIO4 4-Channel Serial I/O Interface - Manual (Page 27)

4-1
Section 4. Programming the SDM-SIO4
This section gives both the basic commands and advanced command line options which
allow testing and advanced configuration of the SDM-SIO4.
4.1 Command Line Operation and Structure
To use the command line mode, connect a computer to port 1 of the SDM-
SIO4. The computer should run a terminal emulation program (e.g.
GraphTerm) which is set to 9600 baud, 8 data bits and 1 stop bit. If connecting
to a PC you will need a null modem cable.
When the computer is connected, the command line can be made active by
pressing the small momentary push-button switch, next to the Status LED.
When this happens the SDM-SIO4 prompt (
SDMSIO4-> ) is sent out of port 1.
At this prompt a number of commands can be typed and executed.
• The command line buffer is 512 bytes long so no command with parameters
must be longer than this.
• After ten minutes of inactivity (where no valid commands are executed) the
command line mode will time out and port 1 will return to its normal
function.
• The command line mode can be activated while the datalogger is running a
program which communicates with the SDM-SIO4. However, all
datalogger activity related to port 1 is ignored.
• Complicated or long string definitions are best set up by editing a text file
which includes the string definition commands. This file can then be sent
out to the SDM-SIO4 once it is configured in the command line mode. The
SDM-SIO4 can accept multiple configuration strings sent within one file.
By using (datalogger) Instruction P113 Command 321 it is
possible to execute a command line command from a datalogger
program. See Section 5 of this manual for further details.
4.2 Entering Commands
A command is executed when a carriage return ( CR ) is sent. This is normally
sent by pressing the ENTER key on a computer. The method of entering control
characters was discussed in Section 3.1, but is repeated here for convenience.
To enter a control character in the range of 0-255 decimal in a filter string,
formatter string or a user string you must use the ‘&hh’ format, where ‘&’
defines the following two characters, ‘hh’, to be a hexadecimal number between
00 and FF. For example, ‘&de’ would be character 222 decimal. To use ‘&’
within the string you must type ‘&&’ (i.e. && = & when in a string).
NOTE