KEPCO BIT 4882F - Manual (Page 36)

4-8
BIT 4882 030507
4.3.6 PROGRAM MESSAGE SYNTAX SUMMARY
• Common commands begin with an asterisk (*).
• Queries end with a question mark (?).
• Program messages consist of a root keyword and, in some cases, one or more message
units separated by a colon (:) followed by a message terminator. Several message units
of a program message may be separated by a semicolon (;) without repeating the root
keyword.
• If a program message has more than one message unit, then a colon (:) must precede
the next keyword in order to set the parser back to the root (otherwise the next keyword
will be taken as a subunit of the previous message unit).
e.g., the command
meas:volt?;curr?
will read output voltage and output current
since both
volt?
and
curr?
are interpreted as subunits of the
meas
command.
• Several commands may be sent as one message; a line feed terminates the message.
Commands sent together are separated by a semicolon (;). The first command in a mes-
sage starts at the root, therefor a colon (:) at the beginning is not mandatory.
e.g., the command
meas:volt?;:curr?
will read output voltage and programmed
current since the colon preceding curr? indicates that
curr?
is not part of the
meas
command and starts at the root.
• UPPER case letters in mnemonics are mandatory (short form). Lower case letters may
either be omitted, or must be specified completely (long form)
e.g., INSTrument (long form) has the same effect as INST (short form).
• Commands/queries may be given in upper/lower case (long form)
e.g., SoUrCe is allowed.
• Text shown between brackets [] is optional.
e.g., :[SOUR]VOLT:[LEV] TRIG has the same effect as :VOLT TRIG
4.3.7 SCPI PROGRAM EXAMPLE
Figure 4-3 is an example of a program using SCPI commands to program an MST Power Sup-
ply. The program illustrated is for a configuration using an IBM PC or compatible with a National
Instruments GPIB interface card. (It will be necessary to consult the manufacturer’s data to
achieve comparable functions with an interface card from a different manufacturer.) This pro-
gram sets output voltage (Voltage mode) or voltage limit (Current mode) to 5V, and current limit
(Voltage mode) or output current (Current mode) to 1A, then reads the measured (actual) volt-
age and current, then prints the measurements.