IAI America DS-S-C1 - Manual (Page 7)

5
l Range of numerical values in SEL
SEL uses two types of numbers, integers and real numbers but are subject to the following limitations.
1. Inside the controller
The range of whole numbers that can be accommodated is ±2,147,483,648 and for real numbers the theoretical range
is ±3.4 x 10
38, as a single precision floating point.
2. Limitations in actual use
The programming tool developed initially was an LCD teaching pendant which resulted in certain constraints with
respect to input and output from the program. The numerical values that can be handled from the program are -
9,999,999~99,999,999 for integers and -999,999~9999,999 or -.999999~.999999, in other words an eight digit
value including the decimal point sign for real numbers. Also, when doing floating point calculations, the significant
figure can only be guaranteed up to 7 digits and it will include errors that are particular to floating points.
3. Position data
Internally, position data is handled as whole number data but during the calculation process, these are incorporated
into real numbers and treated as real numbers. There are no problems when dealing with numbers ±9999.999 but
when these are internally calculated as general data and not position data (repeated multipliying and dividing), a
problem arises with the accuracy of the last digit.
When using the Super SEL, please pay close attention to these points. In particular, if you use the CPEQ command in
a comparative calculation using real numbers, you will see almost no correlation. In this case, you will need to use
the CPLE/CPGE command which can view the large and small relations in parallel.
1.2 Symbols used in SEL Language
1. Numerals and Symbols in SEL Language
SYMBOL MEANING EXAPLANATION
ZR Zero When calculation results are 0, post turns ON
EQ Equal When operand 1 = operand 2, post turns ON
NE Not equal When operand 1
≠
operand 2, post turns ON
GT Greater tham When operand 1
>
operand 2, post turns ON
GE Greater or equal to When operand 1
≥
operand 2, post turns ON
LT Less than When operand 1
<
operand 2, post turns ON
LE Less than or equal to When operand 1
<
operand 2, post turns ON
PE Position end When movement is comeplete, post turns ON
(turns ON 2 points before the end of path, circular and
arc moves when used in successive, consecutive lines of code)
CP Complete When the command is completed, post turns ON
TU Time up After the time has elapsed, post turns ON
XX No position data When there is no valid value in the position, post turns ON
ON ON On
OF OFF Off
NT Not Invert
FN Forward ON Moves forward while the designated I/O · flag is ON
FF Forward OFF Moves forward while the designated I/O · flag is OFF
BN Backward ON Moves backward while the designated I/O · flag is ON
BF Backward OFF Moves backward while the designated I/O · flag is OFF