Keithley 6487 Reference Manual page 159

9-14 Remote Operation
Multiple command messages
You can send multiple command messages in the same program message as long as they
are separated by semicolons (;). The following is an example showing two commands in
one program message:
:stat:oper; :stat:oper:enab <NRf>
When the above is sent, the first command word is recognized as the root command (:stat).
When the next colon is detected, the path pointer moves down to the next command level
and executes the command. When the path pointer sees the colon after the semicolon (;), it
resets back to the root level and starts over.
Commands that are on the same command level can be executed without having to retype
the entire command path. Example:
:stat:oper:enab <NRf>; enab?
After the first command (:enab) is executed, the path pointer is at the third command level
in the structure. Since :enab? is also on the third level, it can be entered without repeating
the entire path name. Notice that the leading colon for :enab? is not included in the pro-
gram message. If a colon were included, the path pointer would reset to the root level and
expect a root command. Since :enab? is not a root command, an error would occur.
Command path rules
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Using common commands and SCPI commands in the same message
Both common commands and SCPI commands can be used in the same message as long
as they are separated by semicolons (;). A common command can be executed at any com-
mand level and will not affect the path pointer.
:stat:oper:enab <NRf>; *ESE <NRf>
Each new program message must begin with the root command, unless it is
optional (e.g., [:SENSe]). If the root is optional, simply treat a command word on
the next level as the root.
The colon (:) at the beginning of a program message is optional and need not be
used.
:stat:pres = stat:pres
When the path pointer detects a colon (:), it moves down to the next command
level. An exception is when the path pointer detects a semicolon (;), which is used
to separate commands within the program message.
When the path pointer detects a colon (:) that immediately follows a semicolon (;),
it resets to the root level.
The path pointer can only move down. It cannot be moved up a level. Executing a
command at a higher level requires that you start over at the root command.
Model 6487 Reference Manual