BOP HIPWR 111315 3-633.6.4.5 DATA SEPARATORData must be separated from the last keyword by a space (e.g., VOLT:LEV:TRIG 14 orSOUR:VOLT? MAX3.6.4.6 MESSAGE UNIT SEPARATORWhen two or more message units are combined in a program message, they must be separatedby a semicolon (;) (e.g., VOLT 15;MEAS:VOLT? and CURR 12; CURR:TRIG 12.5).3.6.4.7 ROOT SPECIFIERThe root specifier is a colon (:) that precedes the first keyword of a program message. Thisplaces the parser at the root (top left, Figure 3-18) of the command tree. Note the differencebetween using the colon as a keyword separator and a root specifier in the following examples:VOLT:LEV:IMM 16 Both colons are keyword separators.: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 TERMINATORThe message terminator defines the end of a message. One message terminator is permitted:• new line (), ASCII 10 (decimal) or 0A (hex)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 addedat the end of each message. Where a message terminator is shown it is representedas regardless of the actual terminator character.3.6.5 UNDERSTANDING THE COMMAND STRUCTUREUnderstanding the command structure requires an understanding of the subsystem commandtree illustrated in Figure 3-18. The “root” is located at the top left corner of the diagram. Theparser goes to the root if:• a message terminator is recognized by the parser• a root specifier is recognized by the parserOptional 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 levelkeyword [SOURce] is an optional keyword. Starting at the root, there are various branches orpaths 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 pathto the next level, so that VOLTage, CURRent, and FUNCtion commands are at the root level.
