Yokogawa GC8000 Process Gas Chromatograph - Manual (Page 501)

<Appendix G User Program>
App.G-2
IM 11B08A01-01E
1.3 Data Types
Integer, real type (single precision real number type) and double precision real number type can
be used.
• Integer Type
Integers in the range of –32768 to 32767 are taken as values.
They are shown internally as 2-byte (16-bit).
• Real Type (single precision real number type)
Real numbers are taken as values. They are shown internally as 4-byte (32-bit).
Signifi cant fi gures are roughly 7-fi gure decimals. Absolute values are in the range of 2.7 ×
10 – 20 to 9.2 × l0 – 18.
• Double Precision Real Number Type
Real numbers are taken as values. They are shown internally as 8-byte (64-bit).
Signifi cant fi gures are roughly 16-fi gure decimals. Absolute values are in the range of 2.7 ×
10 – 20 to 9.2 × l0 – 18.
1.4 Constants
 Numeric Constants
The following numeric constants can be used.
(1) Expressed without decimal point or exponential part. Example: 10, –10
(2) Expressed with decimal point but without exponential part. Example: 0.12, –0.145
(3) Expressed with both decimal point and exponential part. Example: 0.35E7, –2.5E–4
(4) Expressed without decimal point but with exponential part. Example: 1E12, –4E–7, 3E+10
Note: Only decimal numbers can be used.
Numeric constants of over 16 digits in length generate a syntax error.
 Character-string constant
Character-string constants can use DP statements.
Usable character-strings are one-byte alphanumeric characters and one-byte special characters.
1.5 Variables
The conditions for GC8000 user script variables are as follows:
(1) Use variables after declaring. Initial value of variable is 0.
(2) Maximum length of variable name is 16 digits.
(3) All variable names must be defi ned in upper-case characters.
(4) Depending on the variable type, the initial character must always start with “I,” “R” or “D.”
When the variable type is INTEGER, the initial character of the variable name is “I.”
When the variable type is REAL, the initial character of the variable name is “R.”
When the variable type is DOUBLE, the initial character of the variable name is “D.”
(5) There is a limitation on the number of variables that can be used to defi ne one script fi le.
(Differs depending on RAM size being used.)
 Numeric Variable
The type of the numeric variable is specifi ed by the statement type declaration (DEFINT,
DEFSNG, DEFDBL). Numeric variables have a maximum of 16 alphanumeric digits that start
with an alphabetic character as follows.
DEFINT: I
DEFSNG: R
2nd Edition : May 11, 2012-00