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PM100USB
Querying Parameter Settings
You can query the current value of most parameters by adding a question mark (
?
) to the com-
mand. For example, the following command sets the operating wavelength to 1550 nm:
"CORR:WAVE 1550"
You can query the operating wavelength by executing:
"CORR:WAVE?"
You can also query the minimum or maximum operating wavelength allowed as follows:
"CORR:WAVE? MIN"
"CORR:WAVE? MAX"
Caution
If you send two query commands without reading the response from the first, and then attempt
to read the second response, you may receive some data from the first response followed by
the complete second response. To avoid this, do not send a query command without reading
the response. When you cannot avoid this situation, send a device clear before sending the
second query command.
SCPI Command Terminators
A command string sent to the power/energy meter must terminate with a <new line> character.
The IEEE-488 EOI (end-or-identify) message is interpreted as a <new line> character and can
be used to terminate a command string in place of a <new line> character. A <carriage return>
followed by a <new line> is also accepted. Command string termination will always reset the
current SCPI command path to the root level.
IEEE488.2 Common Commands
The IEEE-488.2 standard defines a set of common commands that perform functions like reset,
self-test, and status operations. Common commands always begin with an asterisk (
*
), are four
to five characters in length, and may include one or more parameters. The command keyword
is separated from the first parameter by a blank space. Use a semicolon (
;
) to separate mul-
tiple commands as shown below:
"*RST; *CLS; *ESE 32; *OPC?"
SCPI Parameter Types
The SCPI language defines several different data formats to be used in program messages
and response messages.
Numeric Parameters Commands that require numeric parameters will accept all commonly
used decimal representations of numbers including optional signs, decimal points, and scientific
notation.
Special values for numeric parameters like
MINimum, MAXimum
and
DEFault
are also ac-
cepted. You can also send engineering unit suffixes with numeric parameters (e.g.,
M,K,
or
u
).
If only specific numeric values are accepted, the power/energy meter will automatically round
the input numeric parameters. The following command uses a numeric parameter:
POWer:REFerence {MINimum|MAXimum|DEFault|<numeric_value>[W]}
Discrete Parameters Discrete parameters are used to program settings that have a limited
number of values (like
W,DBM
) . They can have a short form and a long form just like command
keywords. You can mix upper- and lower-case letters. Query responses will always return the
short form in all upper-case letters. The following command uses discrete parameters:
POW:UNIT {W|DBM}