C-Link Protocol Commands
Commands
B-2
Model 48
i
Instruction Manual
Thermo Fisher Scientific
For example, if the instrument ID is set to 48, then each command must
begin with the ACSII character code 176 decimal. The analyzer ignores any
command that does not begin with its instrument identification number. If
the instrument ID is set to 0, then this byte is not required. For more
information on changing Instrument ID, see Chapter 3, “
Operation
”.
The analyzer must be in the remote mode in order to change instrument
parameters via remote. However, the command “set mode remote” can be
sent to the analyzer to put it in the remote mode. Report commands
(commands that don’t begin with “set”) can be issued either in the remote
or local mode. For information on changing modes, see Chapter 3,
“Operation”.
The commands can be sent in either uppercase or lowercase characters.
Each command must begin with the proper instrument identification
number (ASCII) character. The command in the following example begins
with the ASCII character code 176 decimal, which directs the command to
the Model 48
i
, and is terminated by a carriage return “CR” (ASCII
character code 13 decimal).
<ASCII 176> T I M E <CR>
Many of the commands have two forms. One form reads parameter from
the instrument’s memory, and the other writes, or updates, a parameter.
The syntax for a write command adds the word “set” in front of the
command and provides an argument. Command responses are generally
echoed with a data element appended.
Note
If the Service Mode is active, C-Link “set” commands are not
allowed. This is to prevent parameters from being changed remotely while
the unit is being serviced locally.
▲
If an incorrect command is sent, an error message is generated. The list of
error responses is shown in
Table B–1
. The following example sends the
incorrect command “set unit ppm” instead of the correct command “set gas
unit ppm.”
Send:
set
unit
ppm
Receive:
set unit ppm bad cmd
Commands
