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Example

In the example, the coil represented by E1 is turned ON whenever reference E2 or E6 is ON.
The coil represented by E1 is turned OFF whenever reference E5 or E3 is ON.

Figure 322

Retentive SET Coil

Retentive SET and RESET coils are similar to SET and RESET coils, but they are retained across
power failure or when the PLC transitions from to Run mode.  A retentive SET coil sets a
discrete reference ON if the coil receives power flow.  The reference remains ON until reset
by a retentive RESET coil.

Retentive SET coils write an undefined result to the transition bit for the given reference.

Retentive RESET Coil

This coil sets a discrete reference OFF if it receives power flow. The reference remains OFF
until set by a retentive SET coil. The state of this coil is retained across power failure or when
the PLC transitions from Stop to Run mode.

Retentive RESET coils write an undefined result to the transition bit for the given reference.

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23.8

Table Functions

The Table functions are used to:

•

Copy array data: ARRAY MOVE

•

Search for values in an array

The maximum length allowed for these functions is 32,767 for any type.

•

Data Types for the Table Functions

Table functions operate on these types of data:

INT

Signed integer

DINT

Double precision signed integer

BIT

Bit data type

BYTE

Byte data type

WORD

Word data type

23.8.1

Table Functions Array Move

The Array Move function copies a specified number of elements from a source array to a
destination array. When the function receives power flow, it copies the number of elements
specified from the input array, starting at the indexed location. The function then writes the
copied elements to the output array starting with the indexed location.

For bit data, when word-oriented memory is selected for the parameters of the source array
and/or destination array starting address, the least significant bit of the specified word is the
first bit of the array.

The indices in an Array Move instruction are 1-based. In using an Array Move, no element
outside either the source or destination arrays (as specified by their starting address and
length) may be referenced.

The OK output receives power flow unless one of the following occurs:

•

Enable is OFF.

•

(N + SNX

–

1) is greater than (length).

•

(N + DNX

–

1) is greater than (length).

Figure 323

Applies to Array Move only.

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Parameters for the Array Move Function

Input/
Output

Choices

Description

enable

flow

When the function is enabled, the operation is
performed.

For all: R, AI, AQ
For INT, BIT, BYTE, WORD: I, Q,
M, T, G,
For BIT, BYTE, WORD: SA, SB, SC

SR contains the starting address of the source array.
For ARRAY_MOVE_ BIT, any reference may be used;
it does not need to be byte aligned.

SNX

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

SNX contains the index of the source array.

DNX

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

DNX contains the index of the destination array.

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

N provides a count indicator.

flow, none

OK is energized whenever enable is energized.

For all: SA, SB, SC, R, AI, AQ
For INT, BIT, BYTE, WORD: I, Q,
M, T, G

The starting address of the destination array. For
ARRAY_MOVE_ BIT, any reference may be used; it
does not need to be byte aligned.

length

The number of elements starting at SR and DS that
make up each array. It is defined as the length of
SR+DS.

Example 1:

In this example, if %R100=3 then %R0003 - %R0007 of the array %R0001 - %R0016 is read
and is written into %R0104 - %R0108 of the array %R0100 - %R0115. (%R001 and %R0100
are declared as type WORD of length 16.)

Figure 324

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Example 2:

Using bit memory for SR and DS, %M0011 - %M0017 of the array %M0009 - %M0024 is read
and then written to %Q0026 - %Q0032 of the array %Q0022 - %Q0037. (%M009 and %Q0022
are declared as type BOOL of length 16).

Figure 325

Example 3:

Using word memory, for SR and DS, the third least significant bit of %R0001 through the
second least significant bit of %R0002 of the array containing all 16 bits of %R0001 and four
bits of %R0002 is read and then written into the fifth least significant bit of %R0100 through
the fourth least significant bit of %R0101 of the array containing all 16 bits of %R0100 and
four bits of %R0101. 0001 and %R0100 are declared as type BOOL of length 20).

Figure 326

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23.8.2

Table Functions Search for Array Values

Use the Search functions listed below to search for values in an array.

•

Search Equal

•

Equal to a specified value.

•

Search Not Equal

•

Not equal to a specified value.

•

Search Greater Than

•

Greater than a specified value.

•

Search Greater Than or Equal

•

Greater than or equal to a specified value.

•

Search Less Than

•

Less than a specified value.

•

Search Less Than or Equal

•

Less than or equal to a specified value.

When the Search function receives power, it searches the specified array. Searching begins
at the starting address (AR) plus the index value (NX).

Figure 327

The search continues until the array element of the search object (IN) is found or until the
end of the array is reached. If an array element is found, the Found Indication (FD) is set ON
and the Output Index (output NX) is set to the relative position of this element within the
array. If no array element is found before the end of the array is reached, the Found
Indication (FD) is set OFF and the Output Index (output NX) is set to zero.

The valid values for input NX are 0 to (length 1). NX should be set to zero to begin searching
at the first element. This value increments by one at the time of execution. The values of
output NX are 1 to (length). If the value of input NX is out-of-range, (i.e. < 0 or > length), its
value is set to the default value of zero.

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Parameters of the Search Functions

Input/
Output

Choices

Description

enable

flow

When the function is enabled, the search is performed.

For all: R, AI, AQ
For INT, BYTE, WORD: I, Q,
M, T, G
For BYTE, WORD: S

Contains the starting address of the array.

Input NX

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

Contains the zero-based index into the array at which
to begin the search.

For all: R, AI, AQ, constant
For INT, BYTE, WORD: I, Q,
M, T, G
For BYTE, WORD: S

IN contains the object of the search.

Output NX I, Q, M, T, G, R, AI, AQ

Holds the one-based position within the array of the
search target.

flow, none

FD indicates that an array element has been found and
the function was successful.

length

1 to 32,767 bytes or words. The number of elements starting at AR that make up

the array to be searched.

Example 1:

The array AR is defined as memory addresses %R0001 - %R0005. When EN is ON, the portion
of the array between %R0004 and %R0005 is searched for an element whose value is equal
to IN. If %R0001 = 7, %R0002 = 9, %R0003 = 6, %R0004 = 7, %R0005 = 7, and %R0100 = 7,
then the search will begin at %R0004 and conclude at %R0004 when FD is set ON and a 4 is
written to %R0101.

Figure 328

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Example 2:

Array AR is defined as memory addresses %AI001 - %AI016. The values of the array elements
are 100, 20, 0, 5, 90, 200, 0, 79, 102, 80, 24, 34, 987, 8, 0, and 500. Initially, %AQ001 is 5.
When EN is ON, each sweep will search the array looking for a match to the IN value of 0.
The first sweep will start searching at %AI006 and find a match at %AI007, so FD is ON and
%AQ001 is 7. The second sweep will start searching at %AI008 and find a match at %AI015,
so FD remains ON and %AQ001 is 15. The next sweep will start at %AI016. Since the end of
the array is reached without a match, FD is set OFF and %AQ001 is set to zero. The next
sweep will start searching at the beginning of the array.

Figure 329

23.9

Timer and Counter Functions

This section describes the timing and counting functions of the Instruction Set. The data
associated with these functions is retentive through power cycles.

•

OnDelay Stopwatch Timer

•

Off-Delay Timer

•

On-Delay Timer

•

Up Counter

•

Down Counter

23.9.1

Time-Tick Contacts

In addition to the Timer functions of the Instruction Set, the VersaMax PLC has four time-tick
contacts.  These  contacts  can  be  used  to  provide  regular  pulses  of  power  flow  to  other
program  functions.  The  four  time-tick  contacts  have  time  durations  of  0.01  second,  0.1
second, 1.0 second, and 1 minute.

The state of these contacts does not change during the execution of the sweep. These
contacts provide a pulse having an equal on and off time duration.

The contacts are referenced as T_10MS (0.01 second), T_100MS (0.1 second), T_SEC (1.0
second), and T_MIN (1 minute).

The following timing diagram represents the on/off time duration of these contacts.

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Figure 330

These time-tick contacts represent specific locations in %S memory.

23.9.2

Function Block Data Required for Timers and Counters

Each timer or counter uses three words (registers) of %R memory to store the following
information:

current value (CV)

word 1

preset value (PV)

word 2

control word

word 3

When you enter a timer or counter, you must enter a beginning address for these three
words (registers). Do not use consecutive registers for the 3-word timer/counter blocks.
Timers and counters will not work if you place the current value of a block on top of the
preset for the previous block.

Figure 331

The control word stores the state of the Boolean inputs and outputs of its associated
function block in the following format:

Figure 332

Bits 0 through 11 are used for timer accuracy; not for counters.

If the Preset Value (PV) is not a constant, PV is normally set to a different location than the
second word.  Some applications use the second word address for the PV, such as using
%R0102 when the bottom data block starts at %R0101.  It is then possible to change the
Preset Value while the timer or counter is running.  The first (CV) and third (Control) words
can be read but should not be written, or the function will not work.

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23.9.3

Timer and Counter Functions On Delay Stopwatch Timer

A retentive On-Delay Stopwatch Timer (ONDTR) increments while it receives power flow
and  holds  its  value  when  power  flow  stops.    Time  may  be  counted  in  tenths  (0.1),
hundredths  (0.01),  or  thousandths  (0.001)  of  a  second.   The  range  is  0  to  +32,767-time
units.  The state of this timer is retentive on power failure; no automatic initialization occurs
at power-up.

When this function first receives power flow, it starts accumulating time (current value).
When this timer is encountered in the ladder logic, its current value is updated.

Figure 333

When the current value equals or exceeds the preset value PV, output Q is energized.  As
long  as  the  timer  continues  to  receive  power  flow,  it  continues  accumulating  until  the
maximum value is reached.  Once the maximum value is reached, it is retained, and output
Q remains energized regardless of the state of the enable input.

If multiple occurrences of the same timer with the same reference address are enabled
during a CPU sweep, the current values of the timers will be the same.

Parameters of the On-Delay Stopwatch Timer Function

Input/
Output

Choices

Description

address R

The function uses three consecutive words (registers) of %R
memory to store the following:

•

Current value (CV)

= word 1.

•

Preset value (PV)

= word 2.

•

Control word

= word 3.

Do not use this address with other instructions.
Careful: Overlapping references cause erratic timer
operation.

enable

flow

When enable receives power flow, the timer’s current value

increments.

flow

When R receives power flow, it resets the current value to
zero.

I ,Q, M, T, G, R, AI, AQ,
constant, none

The Preset Value, which is used when the timer is enabled or
reset.

flow, none

Output Q is energized when the current value of the timer is
greater than or equal to the preset value.

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Input/
Output

Choices

Description

time

tenths (0.1), hundredths
(0.01), or thousandths
(0.001) of seconds

Time increment for the low bit of the PV preset and CV
current value.

Operation of the On-Delay Timer Function

Figure 334

ENABLE goes high; timer starts accumulating

Current value reaches preset value PV; Q goes high

RESET goes high; Q goes low, accumulated time is reset (CV=0)

RESET goes low; timer then starts accumulating again

ENABLE goes low; timer stops accumulating. Whatever time has been
accumulated remains.

ENABLE goes high again; timer starts accumulating time from the earlier
accumulated value.

Current value becomes equal to preset value PV; Q goes high. Timer continues to
accumulate time until ENABLE goes low, RESET goes high or current value becomes
equal to the maximum time

ENABLE goes low; timer stops accumulating time.

When power flow to the timer stops, the current value stops incrementing and is retained.
Output Q, if energized, will remain energized.  When the function receives power flow again,
the current value again increments, beginning at the retained value.  When reset R receives
power flow, the current value is set back to zero and output Q is de-energized unless PV
equals zero.

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Example

In the example, a retentive On-Delay Timer is used to create a signal (%Q0011) that turns on
8.0 seconds after %Q0010 turns on, and turns off when %Q0010 turns off.

Figure 335

23.9.4

Timer and Counter Functions On Delay Timer

The On-Delay Timer (TMR) increments while it receives power flow and resets to zero when
power flow stops. Time may be counted in tenths of a second (the default selection),
hundredths of a second, or thousandths of a second. The range is 0 to +32,767-time units.
The state of this timer is retentive on power failure; no automatic initialization occurs at
power-up.

Figure 336

When the On-Delay Timer function receives power flow, the timer starts accumulating time
(current value). The current value is updated when it is encountered in the logic to reflect
the total elapsed time the timer has been enabled since it was last reset.

If multiple occurrences of the same timer with the same reference address are enabled
during a CPU sweep, the current values of the timers will be the same.

This update occurs as long as the enabling logic remains ON.  When the current value equals
or exceeds the preset value PV, the function begins passing power flow to the right.  The
timer continues accumulating time until the maximum value is reached.  When the enabling
parameter transitions from ON to OFF, the timer stops accumulating time, and the current
value is reset to zero.

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Parameters for the On Delay Timer Function

Input/
Output

Choices

Description

address

The function uses three consecutive words (registers) of
%R memory to store the following:

•

Current value (CV) = word 1.

•

Preset value (PV)

= word 2.

•

Control word

= word 3.

Do not use this address with other instructions.
Careful: Overlapping references cause erratic operation of
the timer.

enable

flow

When enable receives power flow, the timer’s current

value is incremented. When the TMR is not enabled, the
current value is reset to zero and Q is turned off.

I Q, M, T, G, R, AI, AQ,
constant, none

PV is the value to copy into the timer’s preset value when

the timer is enabled or reset.

flow, none

Output Q is energized when TMR is enabled and the
current value is greater than or equal to the preset value.

time

tenths (0.1), hundredths
(0.01), or thousandths
(0.001) of seconds

Time increment for the low bit of the PV preset and CV
current value.

Operation of the On-Delay Timer Function

Figure 337

ENABLE goes high; timer begins accumulating time.

Current value reaches preset value PV; Q goes high, and timer continues
accumulating time.

ENABLE goes low; Q goes low; timer stops accumulating time and current time is
cleared.

ENABLE goes high; timer starts accumulating time.

ENABLE goes low before current value reaches preset value PV; Q remains low;
timer stops accumulating time and is cleared to zero (CV=0).

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Example

In the example, a delay timer (with address) TMRID is used to control the length of time that
coil is on. This coil has been assigned the Nickname DWELL. When the normally open
(momentary) contact with the Nickname DO_DWL is on, coil DWELL is energized.

The contact of coil DWELL keeps coil DWELL energized (when contact DO_DWL is released),
and also starts the timer TMRID.  When TMRID reaches its preset value of one-half second,
coil REL energizes, interrupting the latched-on condition of coil DWELL.  The contact DWELL
interrupts power flow to TMRID, resetting its current value and de-energizing coil REL.  The
circuit is then ready for another momentary activation of contact DO_DWL.

Figure 338

23.9.5

Timer and Counter Functions Off Delay Timer

The Off-Delay Timer increments while power flow is off, and resets to zero when power flow
is on. Time may be counted in tenths (0.1), hundredths (0.01), or thousandths (0.001) of a
second. The range is 0 to +32,767-time units. The state of this timer is retentive on power
failure; no automatic initialization occurs at power-up.

Figure 339

When the Off-Delay Timer first receives power flow, it passes power to the right, and the
current value (CV) is set to zero. The function uses word 1 as its CV storage location. The
output remains on as long as the function receives power flow. If the function stops
receiving power flow from the left, it continues to pass power to the right, and the timer
starts accumulating time in the current value.

If multiple occurrences of the same timer with the same reference address are enabled
during a CPU sweep, the current values of the timers will be the same.

The Off-Delay Timer does not pass power flow if the preset value is zero or negative.

Each time the function is invoked with the enabling logic set to OFF, the current value is
updated to reflect the elapsed time since the timer was turned off. When the current value
(CV) is equal to the preset value (PV), the function stops passing power flow to the right.

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When that occurs, the timer stops accumulating. When the function receives power flow
again, the current value resets to zero.

When the Off-Delay Timer is used in a program block that is not called every sweep, the
timer accumulates time between calls to the program block unless it is reset.  This means
that it functions like a timer operating in a program with a much slower sweep than the
timer in the main program block.  For program blocks that are inactive for a long time, the
timer should be programmed to allow for this catch-up feature.  For example, if a timer in a
program block is reset and the program block is not called (is inactive) for four minutes,
when the program block is called, four minutes of time will already have accumulated.  This
time is applied to the timer when enabled, unless the timer is first reset.

Example

In the example, an Off-Delay Timer is used to turn off an output (%Q00001) whenever an
input (%I00001) turns on. The output is turned on again 0.3 seconds after the input goes
off.

Figure 340

Operation of the Off-Delay Timer Function

Figure 341

ENABLE and Q both go high; timer is reset (CV = 0).

ENABLE goes low; timer starts accumulating time.

CV reaches PV; Q goes low, and timer stops accumulating time.

ENABLE goes high; timer is reset (CV = 0).

ENABLE goes low; timer starts accumulating time.

ENABLE goes high; timer is reset (CV = 0).

ENABLE goes low; timer begins accumulating time.

CV reaches PV; Q goes low, and timer stops accumulating time.

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Parameters of the Off-Delay Timer Function

Input/
Output

Choices

Description

address

The function uses three consecutive words (registers) of %R
memory to store the following:

•

Current value (CV) = word 1.

•

Preset value (PV)

= word 2.

•

Control word

= word 3.

Do not use this address with other instructions.
Careful: Overlapping references cause erratic operation of
the timer.

enable

flow

When enable receives power flow, the timer’s current

value is reset to 0.

I Q, M, T, G, R, AI, AQ,
constant, none

PV is the value to copy into the timer’s preset value when

the timer is enabled or reset. For a register (%R) OV
reference, the PV parameter is specified as the second
word of the address parameter. For example, an address
parameter of %R0001 would use %R0002 as the PV
parameter.

flow, none

Output Q is energized when the current value is less than
the preset value. The Q state is retentive on power failure;
no automatic initialization occurs at power-up.

time

tenths (0.1), hundredths
(0.01), or thousandths
(0.001) of seconds

Time increment for the low bit of the PV preset and CV
current value.

23.9.6

Timer and Counter Functions Up Counter

The Up-Counter function counts up to a designated value. The range is 0 to +32,767 counts.
When the Up-Counter reset is ON, the current value of the counter resets to 0. Each time
the enable input transitions from OFF to ON, the current value increments by 1. The current
value can be incremented past the preset value PV. The output is ON whenever the current
value is greater than or equal to the preset value. The state of the CTU is retentive on power
failure; no automatic initialization occurs at power-up.

Figure 342

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Parameters of the Up-Counter Function

Input/
Output

Choices

Description

address

The function uses three consecutive words (registers) of %R memory
to store the following:

•

Current value (CV) = word 1.

•

Preset value (PV)

= word 2.

•

Control word

= word 3.

Do not use this address with another up counter, down counter, or
any other instruction or improper operation will result.
Careful: Overlapping references cause erratic operation of the
counter.

enable

flow

On a positive transition of enable, the current count is incremented
by one.

flow

When R receives power flow, it resets the current value back to zero.

I, Q, M, T, G, R,
AI, AQ,
constant, none

PV is the value to copy into the counter’s preset value when the

counter is enabled or reset.

flow, none

Output Q is energized when the current value is greater than or
equal to the preset value.

Example of the Up-Counter Function

In the example, every time input %I0012 transitions from OFF to ON, up counter PRT_CNT
counts up by 1; internal coil %M0001 is energized when 100 parts have been counted. When
%M0001 is ON, the accumulated count is reset to zero.

Figure 343

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