10-4
IM 755601-01E
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
: LIMit?<PMT>
→
:LIMIT:MODE PCNT;PCNT:
REFERENCE 1.0000E+05;PLIMIT 9.99;
DATA 5.00,—5.00
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 ”
HEADer
” can also be written as “
header
”
or “
Header
.”
• The lower-case section of the header can be omitted.
Example “
HEADer
” can also be writen as “
HEADE
” or
“
HEAD
.”
• 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 “
HEADer?
” is
“
HEAD?
.”
• 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
LIMit[:MODE]
can be written as “
LIM
.”
However, the last section enclosed by
braces ([])cannot be omitted in a upper-
level query.
Example “
LIMit?
” and “
LIMit:MODE?
” are different
queries.
10.1.3
Responses
When the controller sends a message unit that has a
question mark (?) in its program header (query), the
instrument returns a response message to the query.
A response message is returned in one of the following
two forms.
• Response consisting of a header and data
If the response can be used as a program message
without any change, it is returned with a command
header attached.
Example
:CHECk:MODE?<PMT>
→
:CHECK:MODE BEFORE<RMT>
• Response consisting of data only
If the response cannot be used as a program
message unless changes are made to it (query-only
command), only the data section is returned.
However, there are query-only commands that
return responses with the header attached.
Example
:STATus ERRor?<PMT>
→
0,”NO ERROR”
When you wish to return a response without a
header
Responses that return both header and data can be
set so that only the data section is returned. Use the
“
COMMunicate:HEADer
” command for this task.
Abbreviated form
The response header is normally returned with the
lower-case section removed. You can change this so
that the response header is in the full form. Use the
“
COMMunicate:VERBose
” command for this task. The
sections enclosed by braces ([ ]) are also omitted in
the abbreviated form.
10.1 Before Programming
