Tektronix KEITHLEY 2200 Series, Programming Reference Manual

Page: 18 / 104

Command Syntax
You can create commands and queries from these subsystem hierarchy trees.
Commands specify actions for the instrument to perform. Queries return
measurement data and information about parameter settings.
Message Terminators This manual uses the term <EOM> (End of message) to represent a message
terminator.
USB End of Message (EOM) terminators.
See the USB Test and Measurement
Class Speci fi cation (USBTMC) section 3.2.1 for details. The power supply
terminates messages by setting the EOM bit in the USB header of the last
transfer of a message to the host (USBTMC Speci
fi cation section 3.3.1), and by
terminating messages with a LF.
When receiving, the power supply expects a LF and an asserted EOM bit as a
message terminator. When using the GPIB interface, the power supply expects a
line feed (LF) as the message terminator.
Parameter types Many power supply commands require parameters. Parameters are indicated
by angle brackets, such as <
fi le_name>. There are several different types of
parameters, as listed in the following table. The parameter type is listed after the
parameter. Some parameter types are de
fi ned speci fi cally for the power supply
command set and some are de fi ned by SCPI. (See Table 2-4.)
Table 2-4: Types of parameters
Parameter type Description Example
boolean Boolean numbers or values
ON
or ≠ 0
OFF
or 0
discrete A list of speci fi c values
MIN, MAX
NR1 numeric Integers 0, 1, 15, -1
NR2 numeric Decimal numbers 1.2, 3.141516, -6.5
NR3 numeric Floating point numbers 3.1415E-9, -16.1E5
NRf numeric Flexible decimal number that
may be type NR1, NR2, or NR3 See NR1, NR2, NR3 examples in
this table
string Alphanumeric characters (must
be within quotation marks) “Testing 1, 2, 3”
2-4 Series 2200 Programmable Multichannel DC Power Supplies Programmer Manual