10.14 MATH FUNCTIONS

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These functions use values in memory, and store the results back in memory (Note: these functions do not use variables like normal programming languages.)

Math functions are quite similar. The following example adds the integer and floating point number and puts the results in `F8:36'.

Basic PLC-5 math functions include,

ADD(value,value,destination) - add two values

SUB(value,value,destination) - subtract

MUL(value,value,destination) - multiply

DIV(value,value,destination) - divide

NEG(value,destination) - reverse sign from positive/negative

CLR(value) - clear the memory location

Consider the example below,

As an exercise, try the calculation below with ladder logic,

Some intermediate math functions include,

CPT(destination,expression) - does a calculation

ACS(value,destination) - inverse cosine

COS(value,destination) - cosine

ASN(value,destination) - inverse sine

SIN(value,destination) - sine

ATN(value,destination) - inverse tangent

TAN(value,destination) - tangent

XPY(value,value,destination) - X to the power of Y

LN(value,destination) - natural log

LOG(value,destination) - base 10 log

SQR(value,destination) - square root

Examples of some of these functions are given below.

For practice implement the following function,

Some functions are well suited to statistics.

AVE(start value,destination,control,length) - average of values

STD(start value,destination,control,length) - standard deviation of values

SRT(start value,control,length) - sort a list of values

Examples of these functions are given below.

There are also functions for basic data conversion.

TOD(value,destination) - convert from BCD to binary

FRD(value,destination) - convert from binary to BCD

DEG(value,destination) - convert from radians to degrees

RAD(value,destination) - convert from degrees to radians

Examples of these functions are given below.