KEPCO BIT 232F - Manual (Page 28)

4-6 BIT 232 022800
4.4.4.4 DATA
Some commands require data to accompany the keyword either in the form of a numeric value
or character string. Data always follows the last keyword of a command or query (e.g.,
VOLT:LEV:TRIG 14 or SOUR:VOLT? MAX
4.4.4.5 DATA SEPARATOR
Data must be separated from the last keyword by a space (e.g., VOLT:LEV:TRIG 14 or
SOUR:VOLT? MAX
4.4.4.6 MESSAGE UNIT SEPARATOR
When two or more message units are combined in a program message, they must be separated
by a semicolon (;) (e.g., VOLT 15;MEAS:VOLT? and CURR 12; CURR:TRIG 12.5).
4.4.4.7 ROOT SPECIFIER
The root specifier is a colon (:) that precedes the first keyword of a program message. This
places the parser at the root (top left, Figure 4-3) of the command tree. Note the difference
between 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.
4.4.4.8 MESSAGE TERMINATOR
The message terminator defines the end of a message. Three message terminators are permit-
ted:
• new line (<NL>), ASCII 10 (decimal) or 0A (hex)
• (<CR>), ASCII 13 (decimal) or 0D (hex)
• both of the above (<CR> <NL>)
NOTE: Kepco power modules 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 <NL> regardless of the actual terminator character.
4.4.5 UNDERSTANDING THE COMMAND STRUCTURE
Understanding the command structure requires an understanding of the subsystem command
tree illustrated in Figure 4-3. 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