8 message terminator, 5 understanding the command structure, Message terminator -59 – KEPCO BOP 1KW-MG Operator Manual, Firmware Ver.2.38 to 2.47 User Manual
Page 123: Understanding the command structure -59
BOP HIPWR 080709
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:CURR:LEV:IMM 4 The first colon is the root specifier, the other two are keyword separators.
VOLT:LEV 6;:CURR:LEV 15 The second colon is the root specifier, the first and third are key-
word separators
:INIT ON;:TRIG;:MEAS:CURR?;VOLT? The first three colons are root specifiers.
3.6.4.8
MESSAGE TERMINATOR
The message terminator defines the end of a message. One message terminator is permitted:
• new line (
NOTE: Kepco power supplies require a message terminator at the end of each program mes-
sage. The examples shown in this manual assume a message terminator will be added
at the end of each message. Where a message terminator is shown it is represented
as
3.6.5
UNDERSTANDING THE COMMAND STRUCTURE
Understanding the command structure requires an understanding of the subsystem command
tree illustrated in Figure 3-18. The “root” is located at the top left corner of the diagram. The
parser goes to the root if:
• a message terminator is recognized by the parser
• a root specifier is recognized by the parser
Optional keywords are enclosed in brackets [ ] for identification; optional keywords can be omit-
ted and the power supply will respond as if they were included in the message. The root level
keyword [SOURce] is an optional keyword. Starting at the root, there are various branches or
paths corresponding to the subsystems. The root keywords for the BOP Power Supply are
:ABORt, :CALibrate, :DISPlay, :INITiate, :LIST, :MEASure, :OUTPut, [:SOURce], :STATus,
:SYSTem and :TRIGger. Because the [SOURce] keyword is optional, the parser moves the path
to the next level, so that VOLTage, CURRent, and FUNCtion commands are at the root level.
Each time the parser encounters a keyword separator, the parser moves to the next indented
level of the tree diagram. As an example, the STATus branch is a root level branch that has
three sub-branches: OPERation, PRESet, and QUEStionable. The following illustrates how
SCPI code is interpreted by the parser:
STAT:PRES
STAT:OPER?;PRES
by the colon in front of OPER?. Thus you can combine the following message units
STAT:OPER? and STAT:PRES;
STAT:OPER:COND?;ENAB 16
abbreviated notation for STAT:OPER:ENAB.