4 data, 5 data separator, Figure 3-10. message structure – KEPCO BOP-GL 1KW Operator Manual Firmware Ver.3.05 and higher User Manual

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BOP-1K-GL 022814

3.7.4.4

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

3.7.4.5

DATA SEPARATOR

Data must be separated from the last keyword by a space (e.g., VOLT:LEV:TRIG 14 or
SOUR:VOLT? MAX

FIGURE 3-10. MESSAGE STRUCTURE

3.7.4.6

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).

3.7.4.7

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 3-9) 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 The root specifier is not necessary for the first keyword and has been omit-
ted. Both colons are keyword separators.

:CURR:LEV:IMM 4 Even though it is not required, it is still correct to include the root specifier
(first colon). The other two are keyword separators.

:CURR:LEV 3.5;:OUTP ON;:CURR?

MESSAGE TERMINATOR

KEYWORD

QUERY INDICATOR

ROOT SPECIFIER

MESSAGE UNIT SEPARATOR

DATA

KEYWORD

KEYWORD SEPARATOR

KEYWORD

MESSAGE UNIT SEPARATOR

DATA

MESSAGE UNIT

DATA SEPARATOR

ROOT SPECIFIER

INITIAL ROOT

SPECIFIER IS

OPTIONAL