8-10
IM 704420-01E
When Concatenating Commands
Command group
A command group is a group of commands that
have common compound headers arranged in a
hierarchy. A command group may contain sub-
groups.
Example
Group of commands related to sampling
SAMPLE?
SAMPLE:ARMING
SAMPLE:ARMING:DELAY:TIME
SAMPLE:ARMING:SLOPE
SAMPLE:ARMING:SOURCE
SAMPLE:GATE?
SAMPLE:GATE:MODE
SAMPLE:GATE:TIME
SAMPLE:INHIBIT?
SAMPLE:INHIBIT:POLARITY
SAMPLE:INHIBIT:STATE
When concatenating commands of the same group
The instrument stores the hierarchical level of the
command that is currently being executed, and
performs analysis on the assumption that the next
command sent will also belong to the same level.
Therefore, common header sections can be omitted
for commands belonging to the same group.
Example;
INPUT:DATA:TRIG:MODE MAN;LEVEL 1.000V<PMT>
When concatenating commands of different
groups
If the following command does not belong to the
same group, a colon (
:
) is placed in front of the
header.
Example;
MEASURE:FUNCTION DTOC;:DISPLAY:SCALE R10<PMT>
When concatenating simple headers
If a simple header follows another command, a
colon (
:
) is placed in front of the simple header.
Example;
MEASURE:FUNCTION DTOC;:START<PMT>
When concatenating common commands
Common commands that are defined in the IEEE
488.2-1992 are independent of hierarchy. Colons
(
:
) are not needed before a common command.
Example;
MEASURE:FUNCTION D3T;*CLS;SPEED 1.0<PMT>
When separating commands with <PMT>
If a terminator is used to separate two commands,
each command is a separate message. Therefore,
the common header must be specified for each
command even when commands belonging to the
same command group are being concatenated.
Example;
MEASURE:FUNCTION D3T<PMT>MEASURE:
SPEED 1.0<PMT>
Upper-level Query
An upper-level query is a query in which a question
mark (
?
) is appended to the highest level command of
a group. Execution of an upper-level query allows all
settings that can be specified in the group to be
received at once. Some query groups which are
comprised of more than three hierarchical levels can
output all the lower level settings.
Example;
SAMPLE?<PMT>
→
:SAMPLE:ARMING:SOURCE AUTO;:
SAMPLE:GATE:MODE TIME;TIME 100.0E–03;:
SAMPLE:INHIBIT:STATE 0
The response to an upper-level query can be
transmitted as a program message back to the
instrument. In this way, the settings that existed when
the upper-level query was made can be restored.
However, some upper-level queries will not return
setup information that is not currently in use. It is
important to remember that not all the group’s
information is necessarily returned as part of a
response.
Header Interpretation Rules
The instrument interprets the header that is received
according to the following rules:
• Upper-case and lower-case letters of a mnemonic
are treated the same.
Example “
MEASure
” can also be written as
“
measure
” or “
Measure
.”
• The lower-case section of the header can be
omitted.
Example “
MEASure
” can also be written as “
MEASU
”
or “
MEAS
.”
• The question mark (
?
) at the end of a header
indicates that it is a query. The question mark (
?
)
cannot be omitted.
Example The shortest abbreviation for “
MEASure?
”
is “
MEAS?
.”
• If the
<x>
(value) at the end of a mnemonic is
omitted, it is interpreted as a
1
.
Example If “
FILTer<x>
” is written as “
FILT
,” it
means “
FILTer1
.”
• The section enclosed by braces (
[]
) can be omitted.
Example “
INPut:PLL[:MODE] 1
” can be written as
“
INPut:PLL 1
.”
However, the last section enclosed by braces (
[]
)
cannot be omitted in an upper-level query.
8.6 Program Format
