Specifying Ratio Measurements; Using Subprogram Memory; Storing A Subprogram - Agilent Technologies 3458A User Manual

Specifying Ratio
To specify ratio measurements, you first select the measurement function for
the signal measurement (and the measurement method for AC or AC+DC
Measurements
voltage) and then enable ratio measurements using the RATIO command.
For example, the following program specifies AC voltage ratio
measurements (on the 10V range) using the synchronous sampling
conversion.
10 OUTPUT 722;"ACV 10"
20 OUTPUT 722; "SETACV SYNC"
30 OUTPUT 722;"RATIO ON"
40 END
Later, to disable ratio measurements, send:
OUTPUT 722;"RATIO OFF"
For ratio measurements, the specified measurement range applies to the
signal voltage measurement only (Input terminals). The reference voltage
measurement (W Sense terminals) is always set to autorange. Ranging is
discussed in detail earlier in this chapter under General Configuration.

Using Subprogram Memory

The multimeter can store command strings as subprograms. This allows you
to execute frequently used command strings while keeping bus/controller
interaction to a minimum. Since stored subprograms are compiled, the
multimeter executes a subprogram much faster than it could execute the
equivalent commands sent over the GPIB. The multimeter has 14k-bytes of
memory that are shared by subprograms and states (discussed later). When
subprogram/state memory becomes full, the multimeter generates the
Memory Error (bit 7 in the error register).
Note
The status register contains a subprogram complete bit that can be used to
determine when a subprogram has finished executing. Refer to Using the
Status Register later in this chapter, for more information.
Storing a
You store a subprogram using the SUB and SUBEND commands. The SUB
command indicates the start of the subprogram and its identifying name. A
Subprogram
subprogram name may contain up to 10 characters. The name can be all alpha
characters or a combination of alpha and numeric characters (the characters
? and _ can also be included in the name). When using an alphanumeric name,
the first character must be alpha. Alpha or alphanumeric subprogram names
must not be the same as multimeter commands or parameters or the name of
a stored state.
Following the SUB command, enter the subprogram commands in the order
you want them executed. Use the SUBEND command to indicate the end of
the subprogram. All subprograms are stored in continuous memory (remain
intact when power is removed) unless the subprogram is compressed (see
Compressing Subprograms later in this chapter). For example, the following
program stores the commands in lines 20 through 60 as a subprogram entitled
Chapter 3 Configuring for Measurements 71