Delta DVP-PLC Instructions for use

PLC

DVP-PLC Application Manual

【Programming】

Table of Contents

Chapter 1 Basic Principles of PLC Ladder Diagram

Foreword: Background and Functions of PLC.......................................................... 1-1

1.1 The Working Principles of Ladder Diagram........................................................ 1-1

1.2 Differences Between Traditional Ladder Diagram and PLC Ladder Diagram........ 1-2

1.3 Edition Explanation of Ladder Diagram ............................................................. 1-3

1.4 How to Edit Ladder Diagram............................................................................. 1-8

1.5 The Conversion of PLC Command and Each Diagram Structure ......................... 1-12

1.6 Simplified Ladder Diagram ............................................................................... 1-15

1.7 Basic Program Designing Examples.................................................................. 1-17

Chapter 2 Functions of Devices in DVP-PLC

2.1 All Devices in DVP-PLC.................................................................................... 2-1

2.2 Values, Constants [K] / [H] ............................................................................... 2-6

2.3 Numbering and Functions of External Input/Output Contacts [X] / [Y].................. 2-8

2.4 Numbering and Functions of Auxiliary Relays [M] .............................................. 2-11

2.5 Numbering and Functions of Step Relays [S]..................................................... 2-11

2.6 Numbering and Functions of Timers [T]............................................................. 2-12

2.7 Numbering and Functions of Counters [C]......................................................... 2-14

2.8 Numbering and Functions of Registers [D], [E], [F]............................................ 2-28

2.8.1 Data register [D] ........................................................................................ 2-28

2.8.2 Index Register [E], [F]................................................................................ 2-29

2.8.3 Functions and Features of File Registers.................................................... 2-30

2.9 Pointer [N], Pointer [P], Interruption Pointer [I].................................................. 2-30

2.10 Special Auxiliary Relays and Special Data Registers........................................ 2-33

2.11 Functions of Special Auxiliary Relays and Special Registers............................. 2-69

2.12 Error Codes................................................................................................... 2-125

Chapter 3 Basic Instructions

3.1 Basic Instructions and Step Ladder Instructions ................................................ 3-1

3.2 Explanations on Basic Instructions ................................................................... 3-3

Chapter 4 Step Ladder Instructions

4.1 Step Ladder Instructions [STL], [RET]............................................................... 4-1

4.2 Sequential Function Chart (SFC) ...................................................................... 4-2

4.3 How does a Step Ladder Instruction Work? ....................................................... 4-3

4.4 Things to Note for Designing a Step Ladder Program......................................... 4-7

4.5 Types of Sequences......................................................................................... 4-9

4.6 IST Instruction................................................................................................. 4-17

Chapter 5 Categories & Use of Application Instructions

5.1 List of Instructions ........................................................................................... 5-1

5.2 Composition of Application Instruction .............................................................. 5-6

5.3 Handling of Numeric Values.............................................................................. 5-11

5.4 E, F Index Register Modification....................................................................... 5-14

5.5 Instruction Index.............................................................................................. 5-16

Chapter 6 Application Instructions API 00-49

●（API00～09）Loop Control .......................................................................... 6-1

●（API10～19）Transmission Comparison....................................................... 6-18

●（API20～29）Four Arithmetic Operation....................................................... 6-32

●（API30～39）Rotation & Displacement......................................................... 6-46

●（API40～49）Data Processing..................................................................... 6-57

Chapter 7 Application Instructions API 50-99

●（API50～59）High Speed Processing........................................................... 7-1

●（API60～69）Handy Instructions.................................................................. 7-39

●（API70～79）Display of External Settings.................................................... 7-59

●（API80～88）Serial I/O ............................................................................... 7-80

Chapter 8 Application Instructions API 100-149

●（API100～109）Communication................................................................... 8-1

●（API110～119）Floating Point Operation...................................................... 8-23

●（API120～129）Floating Point Operation ..................................................... 8-31

●（API130～139）Floating Point Operatio ....................................................... 8-43

●（API140～149）Others................................................................................ 8-55

Chapter 9 Application Instructions API 150-199

●（API150～154）Others................................................................................ 9-1

●（API155～159）Position Control.................................................................. 9-14

●（API160～169）Real Time Calendar ............................................................ 9-39

●（API170～171）Gray Code Conversion........................................................ 9-49

●（API172～175）Floating Point Operation ..................................................... 9-51

●（API180～190）Matrix................................................................................. 9-59

●（API191～199）Positioning Instruction ........................................................ 9-76

Chapter 10 Application Instructions API 215-246

●（API202～203）Others................................................................................ 10-1

●（API215～223）Contact Type Logic Operation Instruction............................. 10-7

●（API224～246）Contact Type Compare Instruction....................................... 10-10

1 Basic Principles of PLC Ladder Diagram

DVP-PLC Application Manual 1-1

Foreword: Background and Functions of PLC

PLC (Programmable Logic Controller) is an electronic device, previously called “sequence controller”. In 1978,

NEMA (National Electrical Manufacture Association) in the United States officially named it as “programmable logic

controller”. PLC reads the status of the external input devices, e.g. keypad, sensor, switch and pulses, and execute by

the microprocessor logic, sequential, timing, counting and arithmetic operations according the status of the input

signals as well as the pre-written program stored in the PLC. The generated output signals are sent to output devices

as the switch of a relay, electromagnetic valve, motor drive, control of a machine or operation of a procedure for the

purpose of machine automation or processing procedure. The peripheral devices (e.g. personal computer/handheld

programming panel) can easily edit or modify the program and monitor the device and conduct on-site program

maintenance and adjustment. The widely used language in designing a PLC program is the ladder diagram.

With the development of the electronic technology and wider applications of PLC in the industry, for example in

position control and the network function of PLC, the input/output signals of PLC include DI (digital input), AI (analog

input), PI (pulse input), NI (numeric input), DO (digital output), AO (analog output), and PO (pulse output). Therefore,

PLC will still stand important in the industrial automation field in the future.

1.1 The Working Principles of Ladder Diagram

The ladder diagram was a diagram language for automation developed in the WWII period, which is the oldest

and most widely adopted language in automation. In the initial stage, there were only A (normally open) contact, B

(normally closed) contact, output coil, timer and counter…the sort of basic devices on the ladder diagram (see the

power panel that is still used today). After the invention of PLC, the devices displayable on the ladder diagram are

added with differential contact, latched coil and the application commands which were not in a traditional power panel,

for example the addition, subtraction, multiplication and division operations.

The working principles of the traditional ladder diagram and PLC ladder diagram are basically the same. The

only difference is that the symbols on the traditional ladder diagram are more similar to its original form, and PLC

ladder diagram adopts the symbols that are easy to recognize and shown on computer or data sheets. In terms of the

logic of the ladder diagram, there are combination logic and sequential logic.

1. Combination Logic

Examples of traditional ladder diagram and PLC ladder diagram for combination logic:

Traditional Ladder Diagram PLC Ladder Diagram

Row 1: Using a normally open (NO) switch X0 (“A” switch or “A" contact). When X0 is not pressed, the contact

will be open loop (Off), so Y0 will be Off. When X0 is pressed, the contact will be On, so Y0 will be On.

1Basic Principles of PLC Ladder Diagram

DVP-PLC Application Manual

1-2

Row 2: Using a normally closed (NC) switch X1 (“B” switch or “B” contact). When X1 is not pressed, the contact

will be On, so Y1 will be On. When X1 is pressed, the contact will be open loop (Off), so Y1 will be Off.

Row 3: The combination logic of more than one input devices. Output Y2 will be On when X2 is not pressed or

X3 and X4 are pressed.

2. Sequential Logic

Sequential logic is a circuit with "draw back” structure, i.e. the output result of the circuit will be drawn back as an

input criterion. Therefore, under the same input criteria, different previous status or action sequence will follow by

different output results.

Examples of traditional ladder diagram and PLC ladder diagram for sequential logic:

Traditional Ladder Diagram PLC Ladder Diagram

When the circuit is first connected to the power, though X6 is On, X5 is Off, so Y3 will be Off. After X5 is pressed,

Y3 will be On. Once Y3 is On, even X5 is released (Off), Y3 can still keep its action because of the draw back (i.e.

the self-retained circuit). The actions are illustrated in the table below.

Devicestatus

Action sequence X5 X6 Y3

1 No action No action Off

2 Action No action On

3 No action No action On

4 No action Action Off

5 No action No action Off

From the table above, we can see that in different sequence, the same input status can result in different output

results. For example, switch X5 and X6 of action sequence 1 and 3 do not act, but Y3 is Off in sequence 1 and

On in sequence 3. Y3 output status will then be drawn back as input (the so-called “draw back”), making the

circuit being able to perform sequential control, which is the main feature of the ladder diagram circuit. Here we

only explain contact A, contact B and the output coil. Other devices are applicable to the same method. See

Chapter 3 “Basic instructions” for more details.

1.2 Differences Between Traditional Ladder Diagram and PLC Ladder Diagram

Though the principles of traditional ladder diagram and PLC ladder diagram are the same, in fact, PLC adopts

microcomputer to simulate the motions of the traditional ladder diagram, i.e. scan-check status of all the input devices

and output coil and calculate to generate the same output results as those from the traditional ladder diagram based

on the logics of the ladder diagram. Due to that there is only one microcomputer, we can only check the program of

the ladder diagram one by one and calculate the output results according to the program and the I/O status before the

cyclic process of sending the results to the output interface Ære-reading of the input status Æcalculation Æoutput.

The time spent in the cyclic process is called the “scan time” and the time can be longer with the expansion of the

program. The scan time can cause delay from the input detection to output response of the PLC. The longer the delay,

1 Basic Principles of PLC Ladder Diagram

DVP-PLC Application Manual 1-3

the bigger the error is to the control. The control may even be out of control. In this case, you have to choose a PLC

with faster scan speed. Therefore, the scan speed is an important specification requirement in a PLC. Owing to the

advancement in microcomputer and ASIC (IC for special purpose), there has been great improvement in the scan

speed of PLC nowadays. See the figure below for the scan of the PLC ladder diagram program.

The output result is calculated

based on the ladder diagram.

(The result has not yet sent to the

external output point, but the

internal device will perform an

immediate output.)

X0 X1

Start

M100 X3

X10

X100 M505

Y126

End

Send the result to the output point

Read input status from outside

Executing in cycles

Besides the difference in the scan time, PLC ladder and traditional ladder diagram also differ in “reverse current”.

For example, in the traditional ladder diagram illustrated below, when X0, X1, X4 and X6 are On and others are Off,

Y0 output on the circuit will be On as the dotted line goes. However, the PLC ladder diagram program is scanned from

up to down and left to right. Under the same input circumstances, the PLC ladder diagram editing tool WPLSoft will be

able to detect the errors occurring in the ladder diagram.

Reverse current of traditional ladder diagram

X0 X1 X2

X3 X4 X5

Reverse current of PLC ladder diagram

X1 X2 Y0

X3 X4 X5

Error detected in the third row

1.3 How to Edit Ladder Diagram

Ladder diagram is a diagram language frequently applied in automation. The ladder diagram is composed of the

symbols of electric control circuit. The completion of the ladder diagram by the ladder diagram editor is the completion

of the PLC program design. The control flow illustrated by diagram makes the flow more straightforward and

acceptable for the technicians of who are familiar with the electric control circuit. Many basic symbols and actions in

1Basic Principles of PLC Ladder Diagram

DVP-PLC Application Manual

1-4

the ladder diagram come from the frequently-seen electromechanical devices, e.g. buttons, switches, relay, timer and

counter, etc. in the traditional power panel for automation control.

Internal devices in the PLC: The types and quantity of the devices in the PLC vary in different brand names.

Though the internal devices in the PLC adopts the names, e.g. transistor, coil, contact and so on, in the traditional

electric control circuit, these physical devices do not actually exist inside the PLC. There are only the corresponding

basic units (1 bit) inside the memory of the PLC. When the bit is “1”, the coil will be On, and when the bit is “0”, the coil

will be Off. The normally open contact (NO or contact A) directly reads the value of the corresponding bit. The

normally close contact (NC or contact B) reads the opposite state of the value of the corresponding bit. Many relays

will occupy many bits. 8 bits equal a “byte”. 2 bytes construct a “word” and 2 words combined is “double word”. Byte,

word or double words are used when many relays are processed (e.g. addition/subtraction, displacement) at the

same time. The other two devices, timer and counter, in the PLC have coil, timer value and counter value and they

have to process some values in byte, word or double word.

All kinds of internal devices in the value storage area in the PLC occupy their fixed amount of storage units.

When you use these devices, you are actually read the contents stored in the form of bit, byte or word.

Introductions on the basic internal devices in the PLC (See Ch 2. Functions of Devices in DVP-PLC for more details.)

Device Functions

Input relay

The input relay is an internal memory (storage) unit in the PLC corresponding to a external

input point and is used for connecting to the external input switches and receiving external

input signals. The input relay will be driven by the external input signals which make it “0” or

“1". Program designing cannot modify the status of the relay, i.e. it cannot re-write the basic

unit of a relay, nor can it force On/Off of the relay by HPP/WPLSoft. SA/SX/SC/EH/EH2/SV

series MPU can simulate input relay X and force On/Off of the relay. But the status of the

external input points will be updated and disabled, i.e. the external input signals will not be read

into their corresponding memories inside PLC, but only the input points on the MPU. The input

points on the extension modules will still operate normally. There are no limitations on the times

of using contact A and contact B of the input relay. The input relays without corresponding input

signals can only be left unused and cannot be used for other purposes.

&Device indication: X0, X1,…X7, X10, X11,… are indicated as X and numbered in octal

form. The No. of input points are marked on MPU and extension modules.

Output relay

The output relay is an internal memory (storage) unit in the PLC corresponding to a external

output point and is used for connecting to the external load. The output relay will be driven by

the contact of an input relay, contacts of other internal devices and the contacts on itself. A

normally open contact of the output relay is connected to the external load. Same as the input

contacts, there are no limitations on the times of using other contacts of the output relay. The

output relay without corresponding output signals can only be left unused and can be used as

input relay if necessary.

&Device indication: Y0, Y1,…Y7, Y10, Y11,…are indicated as Y and numbered in octal

form. The No. of output points are marked on MPU and extension modules.

1 Basic Principles of PLC Ladder Diagram

DVP-PLC Application Manual 1-5

Internal relay

The internal relay does not have connection with the external. It is an auxiliary relay inside the

PLC with the functions same as those of the auxiliary (middle) relay in the electric control

circuit. Every internal relay corresponds to a basic internal storage unit and can be driven by

the contacts of the input relay, contacts of the output relay and the contacts of other internal

devices. There are no limitations on the times of using the contacts of the internal relay and

there will be no output from the internal relay, but from the output point.

&Device indication: M0, M1,…, M4095 are indicated as M and numbered in decimal form.

Step

DVP series PLC offers a step-type control program input method. STL instruction controls the

transfer of step S, which makes it easy for the writing of the control program. If you do not use

any step program in the control program, step S can be used as a internal relay M as well as an

alarm point.

&Device indication: S0, S1,…S1023 are indicated as S and numbered in decimal form.

Timer

The timer is used for timing and has coil, contact and register in it. When the coil is On and the

estimated time is reached, its contact will be enabled (contact A closed, contact B open). Every

timer has its fixed timing period (unit: 1ms/10ms/100ms). Once the coil is Off, the contact iwlwl

be disabled (contact A open, contact B closed) and the present value on the timer will become

“0”.

&Device indication: T0, T1,…,T255 are indicated as T and numbered in decimal form.

Different No. refers to different timing period.

Counter

The counter is used for counting. Before using the counter, you have to give the counter a set

value (i.e. the number of pulses for counting). There are coil, contact and registers in the

counter. When the coil goes from Off to On, the counter will regard it as an input of 1 pulse and

the present value on the counter will plus “1”. We offer 16-bit and 32-bit high-speed counters

for our users.

&Device indication: C0, C1,…,C255 are indicated as C and numbered in decimal form.

Data register

Data processing and value operations always occur when the PLC conducts all kinds of

sequential control, timing and counting. The data register is used for storing the values or all

kinds of parameters. Every register is able to store a word (16-bit binary value). Double words

will occupy 2 adjacent data registers.

&Device indication: D0, D1,…,D9,999 are indicated as D and numbered in decimal form.

1Basic Principles of PLC Ladder Diagram

DVP-PLC Application Manual

1-6

File register

The file register is used for storing the data or all kinds of parameters when the data registers

required for processing the data and value operations are insufficient. Every file register is able

to store a 16-bit word. Double words will occupy 2 adjacent file registers. In SA/SX/SC series

MPU, there are 1,600 file registers. In EH/EH2/SV series MPU, there are 10,000 file registers.

There is not an actual device No. for a file register. The reading and writing of file registers

should be executed by instructions API 148 MEMR, API 149 MEMW, or through the peripheral

device HPP02 and WPLSoft.

&Device indication: K0 ~ K9,999, numbered in decimal form.

Index register

E and F index registers are 16-bit data registers as other data registers. They can be read and

written and can be used in word devices, bit devices or as a constant for index indication.

&Device indication: E0 ~ E7, F0 ~ F7 are indicated as E and F and numbered in decimal

form.

The structure of a ladder diagram:

Structure Explanation Instruction Devices Used

Normally open, contact A LD X, Y, M, S, T, C

Normally closed, contact B LDI X, Y, M, S, T, C

Normally open in series

connection AND X, Y, M, S, T, C

Normally closed in series

connection ANI X, Y, M, S, T, C

Normally open in parallel

connection OR X, Y, M, S, T, C

Normally closed in parallel

connection ORI X, Y, M, S, T, C

Rising-edge trigger switch LDP X, Y, M, S, T, C

Falling-edge trigger switch LDF X, Y, M, S, T, C

Rising-edge trigger in series

connection ANDP X, Y, M, S, T, C

Falling-edge trigger in series

connection ANDF X, Y, M, S, T, C

Rising-edge trigger in parallel

connection ORP X, Y, M, S, T, C

Falling-edge trigger in parallel

connection ORF X, Y, M, S, T, C

Block in series connection ANB -

Block in parallel connection ORB -

Table of contents

Popular Controllers manuals by other brands

Digiplex

Digiplex DGP-848 Programming guide

YASKAWA

YASKAWA SGM series user manual

Sinope

Sinope Calypso RM3500ZB installation guide

Isimet

Isimet DLA Series Style 2 Installation, Operations, Start-up and Maintenance Instructions

LSIS

LSIS sv-ip5a user manual

Rockwell Automation

Rockwell Automation 1769-L31 installation instructions

Airflow

Airflow Uno hab Installation and operating instructions

ABB

ABB ACS580-01 drives Hardware manual

Panasonic

Panasonic GM1 Series Reference manual

Emerson

Emerson SW93 owner's manual

AutoAqua

AutoAqua Smart ATO micro SATO-120P manual

Panasonic

Panasonic FP? Positioning Unit RTEX Technical manual

Samson

Samson Type 5824 Mounting and operating instructions

Alpha IP

Alpha IP MIOB 21001 manual

Siemens

Siemens OpenAir GMA 1 Series Mounting instructions

Surecom

Surecom SR-629 user manual

Fishman

Fishman TriplePlay installation guide

Regulus

Regulus SRS1 T Installation and operation manual