HP 53150A Series Programming Manual page 60

Chapter 3 Programming Your Counter for Remote Operation
Using Multiple Commands
When multiple subsystem commands are sent in one program message,
the first command is always referenced to the root node. Subsequent
commands, separated by ";", are referenced to the same level as the
preceding command if no ":" is present immediately after the command
separator (the semicolon).
For example, sending :SENS:AVER:COUN 5; STAT ON is equivalent to
sending:
:SENS:AVER:COUN 5
:SENS:AVER:STAT ON
or
:SENS:AVER:COUN 5;:SENS:AVER:STAT ON
The ":" must be present to distinguish another root level command. For
example:
:SENS:AVER:COUN 5;:INIT:CONT OFF
is equivalent to sending:
:SENS:AVER:COUN 5
:INIT:CONT OFF
If the ":"(which is following the ";" and is in front of INIT) is omitted, the
Counter assumes that the second command is ":SENS:AVER:INIT:CONT
OFF" and generates a syntax error.
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