Chapter 6 509
Programming Fundamentals
SCPI Language Basics
Programming Fundamentals
SCPI Termination and Separator Syntax
A terminator must be provided when an instrument is controlled using
RS-232. There are several issues to be understood about choosing the
proper SCPI terminator and separator when this is the case. There is
no current SCPI standard for RS-232. Although one intent of SCPI is to
be interface independent, <END> is only defined for IEEE 488
operation. At the time of this writing, the RS-232 terminator issue was
in the process of being addressed in IEEE standard 1174.
A semicolon (;) is not a SCPI terminator, it is a separator. The purpose
of the separator is to queue multiple commands or queries in order to
obtain multiple actions and/or responses. Make sure that you do not
attempt to use the semicolon as a terminator when using RS-232
control.
All binary trace and response data is terminated with <NL><END>, as
defined in Section 8.5 of IEEE Standard 488.2-1992, IEEE Standard
Codes, Formats, Protocols and Common Commands for Use with
ANSI/IEEE Std 488.1-1987.NewYork,NY,1992.
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