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23.3.1

Data Move Functions
Move Data

The MOVE function copies data as individual bits from one location to another. Because the
data is copied in bit format, the new location does not need to be the same data type as the
original.

When the Move function receives power flow, it copies data from input parameter IN to
output  parameter  Q  as  bits.    If  data  is  moved  from  one  location  in  discrete  memory  to
another,  (for  example,  from  %I  memory  to  %T  memory),  the  transition  information
associated with the discrete memory elements is updated to indicate whether or not the
Move operation caused any discrete memory elements to change state.  Data at the input
parameter does not change unless there is an overlap in the source and destination.

Figure 276

Note that if an array of Bit-type data specified in the Q parameter does not include all the
bits in a byte, the transition bits associated with that byte (which are not in the array) are
cleared when the Move function receives power flow.

The input IN can be either a reference for the data to be moved or a constant.  If a constant
is  specified,  then  the  constant  value  is  placed  in  the  location  specified  by  the  output
reference.  For example, if a constant value of 4 is specified for IN, then 4 is placed in the
memory location specified by Q.  If the length is greater than 1 and a constant is specified,
then  the  constant  is  placed  in  the  memory  location  specified  by  Q  and  the  locations
following, up to the length specified. Do not allow overlapping of IN and Q parameters.

The result of the Move depends on the data type selected for the function, as shown below.
For example, if the constant value 9 is specified for IN and the length is 4, then 9 is placed in
the bit memory location specified by Q and the three locations following:

Figure 277

The function passes power to the right whenever power is received.

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Parameters for the Move Data Function

Input/
Output

Choices

Description

enable

flow

When the function is enabled, the move is performed.

Length

The number of bits, words, or double words of data to be
copied. This is the length of IN. Length must be from 1 to 256
for all types except BOOL. If IN is a constant and Q is type BOOL,
the length must be between 1 and 16. If IN is type BOOL, the
length must be between 1 and 256 bits.

I, Q, M, T, G, R, AI, AQ,
constant
For bit or word data
only: S
For real data: R, AI, AQ

IN contains the value to be moved. For MOVE BOOL, any
discrete reference may be used; it does not need to be byte
aligned. However, 16 bits, beginning with the reference
address specified, are displayed online.

flow, none

The OK output is energized whenever the function is enabled.

I, Q, M, T, G, R, AI, AQ,
For bit/ word data: SA,
SB, SC
For real data: R, AI, AQ

When the move is performed, the value at IN is written to Q.
For MOVE BOOL, any discrete reference may be used; it does
not need to be byte aligned. However, 16 bits, beginning with
the reference address specified, are displayed online.

23.3.2

Data Move Functions
Block Move

The Block Move function copies a block of seven constants to a specified location. When the
Block Move function receives power flow, it copies the constant values into consecutive
locations beginning at the destination specified in output Q. The function passes power to
the right whenever power is received.

Figure 278

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Parameters of the Block Move Function

Input/
Output

Choices

Description

enable

flow

When the function is enabled, the block move is performed.

IN1 to
IN7

constant

IN1 through IN7 contain seven constant values.

flow, none

The OK output is energized whenever the function is enabled.

I, Q, M, T, G, R, AI, AQ
For Word data: SA, SB,
SC
For Real data: R, AI,
AQ

Output Q contains the first element of the moved array. IN1 is
moved to Q.

Revision 2.6 and later Micro-64 PLCs, Micro-20 PLCs and Micro-40 PLCs support both
DWORD and DINT data types for a Block Move. Other Micro PLC models do not support 32-
bit data types.

Example

In the example, when the enabling input represented by the nickname FST_SCN is ON, the
Block Move function copies the input constants into memory locations %R0010

–

16.

Figure 279

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23.3.3

Data Move Functions
Block Clear

The Block Clear function fills a specified block of data with zeros. When the function receives
power flow, it writes zeros into the memory location beginning at the reference specified by
IN. When the data to be cleared is from discrete memory (%I, %Q, %M, %G, or %T), the
transition information associated with the references is also cleared.

The function passes power to the right whenever power is received.

Figure 280

Parameters of the Block Clear Function

Input/
Output

Choices

Description

enable

flow

When the function is enabled, the array is cleared.

I, Q, M, T, SA, SB, SC, G,
R, AI, AQ

IN contains the first word of the array to be cleared. The
length of IN must be between 1 and 256 words.

Length

The number of words that will be cleared. This is the length
of IN.

flow, none

The OK output is energized whenever the function is
enabled.

Example

In the example, at power-up, 32 words of %Q memory (512 points) beginning at %Q0001
are filled with zeros. %Q is defined as WORD of length 32.

Figure 281

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23.3.4

Data Move Functions
Shift Register

The  Shift  Register  function  shifts  one  or  more  data  words  or  data  bits  from  a  reference
location into a specified area of memory.  For example, one word might be shifted into an
area of memory with a specified length of five words.  As a result of this shift, another word
of data would be shifted out of the end of the memory area.

The reset input (R) takes precedence over the function enable input. When the reset is
active, all references beginning at the shift register (ST) up to the length specified for LEN,
are filled with zeros.

If  the  function  receives  power  flow  and  reset  is  not  active,  each  bit  or  word  of  the  shift
register  is  moved  to  the  next  highest  reference.    The  last  element  in  the  shift  register  is
shifted into Q.  The highest reference of the shift register element of IN is shifted into the
vacated element starting at ST.  The contents of the shift register are accessible throughout
the program because they are overlaid on absolute locations in logic addressable memory.

Figure 282

Parameters of the Shift Register Function

Input/
Output

Choices

Description

enable

flow

When enable is energized and R is not, the shift is performed.

Length

1 to 256 bits
or words.

The length of the shift register in bits or words. Length is defined as the
length of IN.

flow

When R is energized, the shift register located at ST is filled with zeros.

I, Q, M, T, S, G,
R, AI, AQ,
constant

IN contains the value to be shifted into the first bit or word of the shift
register. For SHFR BIT, any discrete reference may be used; it does not
need to be byte aligned.

I, Q, M, T, SA,
SB, SC, G, R,
AI, AQ

ST contains the first bit or word of the shift register. For SHFR BIT, any
discrete reference may be used; it does not need to be byte aligned.

flow, none

OK is energized whenever the function is enabled and R is not enabled.

I, Q, M, T, SA,
SB, SC, G, R,
AI, AQ

Output Q contains the bit or word shifted out of the shift register. For
SHFR BIT, any discrete reference may be used; it does not need to be
byte aligned.

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CAUTION

The use of overlapping input and output reference address ranges in multi-word functions
is not recommended; it may produce unexpected results.

Example 1:

In the example, the shift register operates on register memory locations %R0001 through
%R0100. (%R0001 is defined as type Word of length 100). When the reset reference CLEAR
is active, the Shift Register words are set to zero.

When the NXT_CYC reference is active and CLEAR is not active, the word from output status
table location %Q0033 is shifted into the Shift Register at %R0001. The word shifted out of
the Shift Register from %R0100 is stored in output %M0005.

Figure 283

Example 2:

In  this  example,  the  Shift  Register  operates  on  memory  locations  %M0001  through
%M0100.  (%M0001 is defined as type Boolean of length 100). When the reset reference
CLEAR is active, the Shift Register function fills %M0001 through %M0100 with zeros.

When NXT_CYC is active and CLEAR is not, the Shift Register function shifts the data in
%M0001 to %M0100 down by one bit. The bit in %Q0033 is shifted into %M0001 while the
bit shifted out of %M0100 is written to %M0200.

Figure 284

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23.3.5

Data Move Functions
Communication Request

The Communication Request (COMMREQ) function is use for specialized communications.
Many types of COMMREQs have been defined. The information below describes only the
basic format of the function.

When the function receives power flow, a command block of data is sent to the specified
module. After sending the COMMREQ, the program can either suspend execution, and wait
for a reply for a maximum waiting period specified in the command, or resume immediately.

Figure 285

Parameters of the COMMREQ Function

Input/
Output

Choices

Description

enable

flow

When the function is energized, the communications request is
performed.

R, AI, AQ

IN contains the first word of the command block.

SYSID

I, Q, M, T, G, R, AI, AQ,
constant

SYSID contains the rack number (most significant byte) and slot
number (least significant byte) of the target device.

TASK

R, AI, AQ, constant

TASK contains the task ID of the process on the target device.

flow, none

FT is energized if an error is detected processing the COMMREQ:
The specified target address is not present (SYSID).
The specified task is not valid for the device (TASK).
The data length is 0.

The device’s status pointer address (in the command block) does

not exist.

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Command Block for the COMMREQ Function

The Command Block starts at the reference specified in COMMREQ parameter IN. The
length of the Command Block depends on the amount of data sent to the device.

The  Command  Block  contains  the  data  to  be  communicated  to  the  other  device,  plus
information  related  to  the  execution  of  the  COMM  REQ.  The  Command  Block  has  the
following structure:

address

Length (in words)

address + 1

Wait/No Wait Flag

address + 2

Status Pointer Memory

address + 3

Status Pointer Offset

address + 4

Idle Timeout Value

address + 5

Maximum Communication Time

address + 6 to
address + 133

Data Block

Example

In the example, when enabling input %M0020 is ON, a Command Block starting at %R0016
is sent to communications task 1 in the device located at rack 1, slot 2 of the PLC. If an error
occurs processing the COMMREQ, %Q0100 is set.

Figure 286

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23.4

Data Type Conversion Functions

The Data Type Conversion functions are used to change a data item from one number type
to another. Many programming instructions, such as math functions, must be used with
data of one type.

•

Convert data to BDC-4

•

Convert data to signed integer

•

Convert data to double-precision integer

•

Convert data to Real

•

Convert data to Word

•

Round a Real number toward zero (TRUN)

23.4.1

Data Type Conversion Functions
Convert Signed Integer Data to BCD-4

The Convert to BCD-4 function outputs the four-digit BCD equivalent of signed integer data.
The original data is not changed by this function. The output data can be used directly as
input for another program function.

Data can be converted to BCD format to drive BCD-encoded LED displays or presets to
external devices such as high-speed counters.

When the function receives power flow, it performs the conversion, making the result
available via output Q. The function passes power flow when power is received, unless the
specified conversion would result in a value that is outside the range 0 to 9999.

Figure 287

Parameters of the Convert to BCD-4 Function

Input/
Output

Choices

Description

enable

flow

When the function is enabled, the conversion is performed.

I, Q, M, T, G, R, AI, AQ,
constant

IN contains a reference for the integer value to be converted to
BCD-4.

flow, none

The OK output is energized when the function is performed
without error.

I, Q, M, T, G, R, AI, AQ Output Q contains the BCD-4 form of the original value in IN.

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Example

In the example, whenever input %I0002 is set and no errors exist, the integer at input
location %I0017 through %I0032 is converted to four BCD digits, and the result is stored in
memory locations %Q0033 through %Q0048. Coil %Q1432 is used to check for successful
conversion.

Figure 288

23.4.2

Data Type Conversion Functions
Convert to Signed Integer

The Convert to Signed Integer function outputs the integer equivalent of BCD-4 or Real
data. The original data is not changed by this function. The output data can be used as input
for another program function.

When the function receives power flow, it performs the conversion, making the result
available via output Q. The function always passes power flow when power is received,
unless the data is out of range.

Figure 289

Parameters of the Convert to Signed Integer Function

Input/
Output

Choices

Description

enable

flow

When the function is enabled, the conversion is
performed.

For BCD-4: I, Q, M, T, G, R, AI, AQ,
constant
For REAL: R, AI, AQ

IN contains a reference for the BCD-4, REAL, or
Constant value to be converted to integer.

flow, none

The OK output is energized whenever enable is
energized, unless the data is out of range or NaN
(Not a Number).

For BCD-4: I, Q, M, T, G, R, AI, AQ
For REAL: R, AI, AQ

Output Q contains the integer form of the original
value in IN.

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Example

In the example, whenever input %I0002 is set, the BCD-4 value in PARTS is converted to a
signed integer and passed to the Addition function, where it is added to the signed integer
value represented by the reference RUNNING. The sum is output by the Addition function
to the reference TOTAL.

Figure 290

23.4.3

Data Type Conversion Functions
Convert to Double Precision Signed Integer

The Convert to Double Precision Signed Integer function outputs the double precision
signed integer equivalent of real data. The original data is not changed by this function. The
output data can be used directly as input for another program function.

Figure 291

Note that loss of precision can occur when converting from Real-type data to Double-
Precision Integer, because Real data has 24 significant bits.

Parameters of the Convert to Double Precision Signed
Integer Function

Input/
Output

Choices

Description

enable

flow

When the function is enabled, the conversion is performed.

I, Q, M, T, G, R, AI, AQ,
constant

Constant or reference for the value to be converted

flow, none

OK is energized whenever enable is energized, unless the real
value is out of range.

R, AI, AQ

Reference that contains the double precision signed integer
form of the original value.

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Example

In the example, whenever input %I0002 is set, the integer value at input location %I0017 is
converted to a double precision signed integer and the result is placed in location %R0001.
The output %Q1001 is set whenever the function executes successfully.

Figure 292

23.4.4

Data Type Conversion Functions
Convert to Real Data

The Convert to Real function outputs the real value equivalent of the input data. The original
data is not changed by this function. The output data can be used directly as input for
another program function.

Note that loss of precision can occur when converting from Double-Precision Integer to Real
data, because since the number of significant bits is reduced to 24.

Figure 293

Parameters of the Convert to Real Function

Input/
Output

Choices

Description

enable

flow

When the function is enabled, the conversion is performed.

R, AI, AQ, constant
For INT only: I, Q, M,
T, G

IN contains a reference for the integer value to be converted to
Real.

flow, none

OK is energized when the function is performed without error.

R, AI, AQ

The Real form of the original value in IN.

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Example

In the example, the integer value of input IN is 678. The result value placed in %T0016 is
678.000.

Figure 294

23.4.5

Data Type Conversion Functions
Convert Real Data to Word Data

The Convert to Word function outputs the Word equivalent of Real data. The original data
is not changed by this function.

Figure 295

Parameters of the Convert to Word Function

Input/
Output

Choices

Description

enable

flow

When the function is enabled, the conversion is performed.

R, AI, AQ, constant

IN contains a reference for the value to be converted to Word
type.

flow, none

OK is energized when the function is performed without error.

I, Q, M, T, G, R, AI, AQ Contains the unsigned integer form of the original value in IN.

Example

Figure 296

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23.4.6

Data Type Conversion Functions
Truncate Real Number

The Truncate function copies a Real number and rounds the copied number down to an
integer or double precision integer. The original data is not changed by this function. The
output data can be used directly as input for another program function.

Figure 297

Parameters of the Truncate Function

Input/
Output

Choices

Description

enable

flow

When the function is enabled, the conversion is performed.

R, AI, AQ, constant

IN contains a reference for the real value to be truncated.

flow, none

The OK output is energized when the function is performed
without error, unless the value is out of range or IN is NaN.

R, AI, AQ
For integer only: I, Q, M,
T, G

Q contains the truncated INT or DINT value of the original
value in IN.

Example

In the example, the displayed constant is truncated, and the integer result 562 is placed in
%T0001.

Figure 298

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23.5

Math and Numerical Functions

This section describes the Math and Numerical functions of the Instruction Set:

•

Standard Math Functions: Addition, Subtraction, Multiplication, Division

•

Modulo Division

•

Scaling Function

•

Square Root

•

Trigonometric functions

•

Logarithmic/Exponential functions

•

Convert to Degrees

•

Convert to Radians

23.5.1

Converting Data for the Math and Numerical Functions

The program may need to include logic to convert data to a different type before using a
Math or Numerical function. The description of each function includes information about
appropriate data types. The section Data Type Conversion Functions explains how to
convert data to a different type.

23.5.2

Math and Numerical Functions
Add, Subtract, Multiply, Divide

The standard math functions are Addition, Subtraction, Multiplication, and Division. The
Division function rounds down; it does not round to the closest integer. (For example, 24
DIV 5 = 4.)

When a math function receives power flow, the appropriate operation is performed on input
parameters IN1 and IN2. Parameters IN1, IN2, and the output Q must be the same data
type.

Figure 299

The standard math functions pass power if there is no math overflow. If an overflow occurs,
the result is the largest value with the proper sign and no power flow.

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Parameters of the Standard Math Functions

Input/
Output

Choices

Description

enable

flow

When the function is enabled, the operation is performed.

IN1

All data types: R, AI, AQ,
constant
INT data type only: I, Q,
M, T, G

IN1 contains a constant or reference for the first value used
in the operation. (IN1 is on the left side of the
mathematical equation, as in IN1 + IN2).
Range for constants in double-precision signed integer
operations is minimum/maximum DINT.

IN2

All data types: R, AI, AQ,
constant
INT data type only: I, Q,
M, T, G

IN2 contains a constant or reference for the second value
used in the operation. (IN2 is on the right side of the
mathematical equation, as in IN1 + IN2). Range for
constants in double-precision signed integer operations is
minimum/maximum DINT.

flow, none

The OK output is energized when the function is performed
without overflow, unless an invalid operation occurs.

All data types: R, AI, AQ
INT only: I, Q, M, T, G

Output Q contains the result of the operation.

Data Types for Standard Math Functions

Standard math functions operate on these types of data:

INT

Signed integer

DINT

Double precision signed integer

REAL

Floating Point

The input and output parameter data types must be the same (16 bits or 32 bits).

23.5.3

Math and Numerical Functions
Add, Subtract, Multiply, Divide

Avoiding Overflows

Be careful to avoid overflows when using Multiplication and Division functions.

If you have to convert Integer to Double-Precision Integer values, remember that the CPU

uses standard 2’s complement with the sign extended to the highest bit of the second word.

You must check the sign of the low 16-bit word and extend it into the second 16 bit word. If
the most significant bit in a 16-bit INT word is 0 (positive), move a 0 to the second word. If
the most significant bit in a 16-bit word is

–

1 (negative), move a

–

1 or hex 0FFFFh to the

second word.

Converting from Double-Precision Integer to Integer data is easier, because the low 16-bit
word (first register) is the integer portion of a Double-Precision Integer 32-bit word. The
upper 16 bits or second word should be either a 0 (positive) or

–

1 (negative) value or the

Double-Precision Integer number will be too big to convert to 16 bits.

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