I/o ports – IAI America PSEL User Manual

Page 86

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76

Part 2 Programs


 If the optional system-memory backup battery is installed, data of global variables and flags will be

retained even after the controller power is turned off.
(Other parameter No. 20 must be set to “2.” Refer to 4.1.2, “When the System Memory Backup Battery
is Used” in Chapter 4 of Part 1.)


 The variables and flags in the local range will be cleared when the program is started.

 Ranges of values that can be used in SEL language

Integers and real numbers can be used. However, pay due attention to the following limitations:


(1) Numeric

data

The PSEL Controller can handle values of maximum eight digits including a sign and a decimal point.
Integer: -9,999,999 to 99,999,999
Real number: Maximum eight digits including a sign and decimal point, regardless of the size of value
Example) 999999.9, 0.123456, -0.12345
If a floating point is used in operations, the number of valid digits will be limited to seven. Also note
that operations using a floating point are subject to error.


(2) Position

data

The input range of position data consists of four integer digits and three decimal digits.
–9999.999 to 9999.999
(The maximum value varies depending on the actuator model.)
If position data are used in internal operations as numeric data (repeated multiplications and
divisions), the precision of the last digit may decrease.

Consider the above limitations fully when using values. Particularly when the CPEQ command is
used in a comparison operation using real numbers, a match will rarely result. In this case, the CPLE
or CPGE command that looks at the magnitude relationship of two terms must be used.


1.2 I/O

Ports

(1) Input

ports

Used as input ports for limit switches, sensor switches, etc.

Input number assignment

000 to 023 (standard)


(2) Output

ports

Used as various output ports.

Output number assignment

300 to 307 (standard)

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