AMETEK Lx Series II Programming Manual - Manual (Page 19)

Programming Manual Lx \ Ls Series II
15
2.3 Using Queries
Observe the following precautions with queries:
Set up the proper number of variables for the returned data.
Read back all the results of a query before sending another command to the AC source.
Otherwise a Query Interrupted error will occur and the unreturned data will be lost.
2.4 Coupled Commands
When commands are coupled it means that the value sent by one command is affected by the
settings of the other commands. The following commands are coupled in the AC source:
the voltage and function shape commands
the step, pulse, and list commands that control output voltages and function shapes
the pulse commands that program the width, duty cycle, period, and the hold parameter
the voltage range and current limit commands
As explained later in chapter 4, the order in which data is sent by these coupled commands can
be important when more than one parameter is changed.
2.5 Structure of a SCPI Message
SCPI messages consist of one or more message units ending in a message terminator. The
terminator is not part of the syntax, but implicit in the way your programming language indicates
the end of a line (such as a newline or end-of-line character).
2.5.1 The Message Unit
The simplest SCPI command is a single message unit consisting of a command header (or
keyword) followed by a message terminator.
ABORt
VOLTage?
The message unit may include a parameter after the header. The parameter usually is
numeric, but it can be a string:
VOLTage 20
VOLTage MAX
2.5.2 Combining Message Units
The following command message is briefly described here, with details in subsequent paragraphs.