A Brief Introduction to the SCPI Language
SCPI Language Basics
The following are some examples of good and bad commands. The examples are created from a theoretical instrument with the simple set of commands indicated below:
[:SENSe]
:POWer
[:RF] :ATTenuation 40dB
:TRIGger
[:SEQuence] :EXTernal [1]
:SLOPe POSitive
[:SENSe]
:FREQuency
:STARt
:POWer
[:RF]
:MIXer
:RANGe
[:UPPer]
Bad Command | Good Command |
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PWR:ATT 40dB | POW:ATT 40dB |
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The short form of POWER is POW, not PWR. |
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FREQ:STAR 30MHz;MIX:RANG | FREQ:STAR |
| 30MHz;POW:MIX:RANG |
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The MIX:RANG command is in the same :SENSE subsystem as FREQ, but executing the FREQ command puts you back at the SENSE level. You must specify POW to get to the MIX:RANG command.
FREQ:STAR 30MHz;POW:MIX RANG | FREQ:STAR |
30MHz;POW:MIX:RANG | |
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MIX and RANG require a colon to separate them. | |
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:POW:ATT 40dB;TRIG:FREQ:STAR | :POW:ATT 40dB;:FREQ:STAR |
2.3GHz | 2.3GHz |
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:FREQ:STAR is in the :SENSE subsystem, not the :TRIGGER subsystem. | |
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:POW:ATT?:FREQ:STAR? | :POW:ATT?;:FREQ:STAR? |
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:POW and FREQ are within the same :SENSE subsystem, but they are two separate commands, so they should be separated with a semicolon, not a colon.
:POW:ATT | :POW:ATT 5dB;:FREQ:STAR |
10MHz | 10MHz |
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Attenuation cannot be a negative value.
