EC20 Series PLC
User Manual

Version V1.1
Revision date June 26, 2006
BOM 31011166




Emerson Network Power provides customers with technical support. Users may contact the nearest
Emerson local sales office or service center.

Copyright © 2005 by Emerson Network Power Co., Ltd.
All rights reserved. The contents in this document are subject to change without notice.

Emerson Network Power Co., Ltd.
Address: No.1 Kefa Rd., Science & Industry Park, Nanshan District 518057, Shenzhen China
Homepage: www.emersonnetworkpower.com.cn
E-mail:





Safety Precautions
To reduce the chance of accident, please read the safety precautions very carefully before operation. The
"Caution, Notice, Warning, Danger" symbols in this manual do not represent all the safety points to be observed,
and are only used as a supplement to various operation safety points. Therefore, the installation and operation

personnel must be strictly trained and master the correct operations and all the safety points before actual
operation.
When operating Emerson PLC products, the safety rules in the industry, the general safety points and special
safety instructions specified in this manual must be strictly observed.
These notices are highlighted in the manual by a warning triangle and are marked as follows according to the
level of danger:
Danger: indicates that death, severe personal injury, or substantial property damage will result if proper
precautions are not taken.
Warning: indicates that death, severe personal injury, or substantial property damage could possibly
result if proper precautions are not taken.
Caution: indicates that minor personal injury or property damage can result if proper precautions are not
taken.
Notes for designing
The programming must include safety circuit to ensure the safe application of the PLC (Programmable Logic
Controller) system upon power off or the PLC malfunction. Note the following when programming:
z The external circuit of the PLC must include the emergency braking circuit, protection circuit, mutual
interlock circuit of forward/reverse rotation, and the interlock switch of position upper/lower limit for
preventing equipment from damage.
z For the safe operation of the equipment and output signals of the serious accident, please design the
external protection circuit and the safety mechanism.
z All the outputs may be shutdown when the CPU of the PLC detects the abnormity of the system; the failure
of part PLC circuit may result in uncontrolled PLC output. A suitable external control circuit must be
designed to ensure the normal operation of the equipment.
z When the PLC output unit such as the relay or the transistor is damaged, the PLC output cannot be
controlled as ON or OFF state.
z The PLC is designed to be used in the electrical environment of indoor area B and C
☆
. However, to prevent
the high lightning voltage from damaging the equipment through the ports of power input, signal input or
control output, a SPD should be installed in the power supply system.

☆: According to IEC61131-2, section 8.3.1 classification declaration
Notes for installation
z Units should not be installed in areas subject to the following conditions: excessive or conductive dust,
corrosive or flammable gas, moisture or rain, excessive heat, regular impact shocks or excessive vibration.
Electric shock, fire hazard and mishandling may also damage the product.
z Take special care not to allow metal debris and wire lead to fall inside the vent of the PLC during the screw
hole processing and wiring. Otherwise there is a danger of fire, damage or faulty operation of equipment.
z Once the installation of the new PLC is complete, remove everything on the surface of the vent, including
packing goods such as protective paper. Otherwise the poor ventilation during the operation may result in
fire, damage or faulty operation of equipment.


z Do not wire, inset or pull out the cable plug with power applied. Otherwise there is a danger of electric
shock or circuit damage.
z Installation and wiring must be fastening and reliable. Bad contact may result in faulty operation of
equipment.
z The input/output cable of high frequency signal should use the shielding cable to improve the interference
rejection of the system.
Notes for wiring
z Installation and wiring can be done only after the external power supplies are all disconnected. Otherwise
there is a danger of electric shock or equipment damage.
z Once the installation and wiring of the PLC is complete, cleanup the spot at once. To prevent the electric
shock, replace the port cover of the product before power is on.
z When wiring AC supplies, the ‘Live’ cable should be connected to the ‘L’ terminal and the ‘Neutral’ cable
should be connected to the ‘N’ terminal. Otherwise the PLC will be damaged.
z Don’t power +24V port of the main module by the external power supply. Otherwise the PLC will be
damaged.
z Do not lay I/O signal cables of the PLC next to other power cables or strong interference circuits.
z Do not make the earth port (PG) of the main module and the heavy current power system share the same
earthing.

Notes for operation and maintenance
z Do not touch the ports when the power is applied, otherwise there is a danger of an electric shock or faulty
operation of equipment.
z The cleaning and the fastening work can be done only after the power supply has been disconnected;
otherwise there is a danger of electric shock.
z Only after the power supply has been disconnected, can the communication signal cables and the cables
of the expansion module or control unit be connected or removed. Otherwise there is a danger of
equipment damage or faulty operation of equipment.
z Do not disassemble the PLC. Otherwise it may destroy the inner electrical components.
z Read through this manual carefully before operating the PLC. Safe and efficient operation of the product,
such as program alternation, trial operation, start and stop, is only based on correct operation and
maintenance.
z Do not replace the button cell battery with power applied. If the battery replacement is indeed to be done
with power applied, it shall always be carried out by adequately trained electric technical personnel
wearing insulated gloves.
Notes for the product disposal
Note the following when disposing the PLC:
z Explosive of the electrolytic capacity: The capacities on the circuit board may explode when burning.
z Exhaust gas when burning: The main body of the PLC is plastic, and it may produce poisonous gas when
burning.
z Disposal of button cell battery: Classified collecting and disposing, and separating from the daily-life
rubbish.
Follow the local environmental regulations to dispose the PLC or dispose it as industrial waste.



Contents
Chapter 1 Preface 1
Chapter 2 Product Introduction 2
2.1 Outline 2

2.2 Maximum Configuration 2
2.3 Internal Memory Capacity Of User Program 2
2.4 Resource Configuration Of System Soft-device 2
2.5 High-speed Input/Output Function 3
2.6 Filter Function Of Input Port 3
2.7 Interrupt Source 3
2.8 Subroutine Call 3
2.9 Reinforced Debugging Function 3
2.10 Support Online Modification 3
2.11 Multiple Password Protection Function 4
2.12 Expansion Module 4
2.13 RUN And STOP Control 4
2.14 User Program Developing And Debugging 4
2.15 Communication And Networking 4
Chapter 3 Installation 5
3.1 Notes For Installation 5
3.2 Requirements For Installation Position 5
3.3 Installation Method 5
3.4 Installation Dimensions 6
Chapter 4 Product Specifications 8
4.1 Model Legend 8
4.2 Product Model And Configuration 8
4.2.1 Main Module 8
4.2.2 I/O Expansion Module 8
4.2.3 Special Function Module 9
4.3 Product Size 9
4.4 Environmental Requirements 9
4.5 Electric Insulation Specifications 9
4.6 Reliability 10
4.7 Power Supply Specifications 10

4.7.1 Inner Power Supply Of Main Module 10
4.7.2 Use Of Each Circuit Output Power 10
4.7.3 Power Specifications Provided By Main Module To Expansion Module 11
4.7.4 Derating Design Of Power Supply Circuit 11


4.7.5 Power Consumption Of Expansion Module 12

4.7.6 Power Capacity Calculation In Expansion Connection 12
4.8 Programming Tool Of User Program 12
Chapter 5 Input Characteristic 13
5.1 User Ports Of Main Module 13
5.2 Input Port Characteristic And Signal Specification 14
5.3 Inner Equivalent Circuit Of Input Port 15
5.4 Input Connection Of High-speed Counter 16
5.5 Interrupt Input Connection 17
5.6 Input Signal Status Indication 17
5.7 Analog Potentiometer And Application 17
5.8 Example Of Input Connection 17
Chapter 6 Output Characteristic 19
6.1 Output Port Application 19
6.2 Electric Specifications Of Output Port 19
6.3 Output Port Connection 20
6.4 Output Port Status Indication 22
6.5 Example Of Output Connection 22
Chapter 7 Expansion Module 23
7.1 Model 23
7.2 Expansion Busbar Connection 23
7.3 Expansion Module Addressing 23
7.3.1 I/O Point Addressing Number Principle 24

7.3.2 Special Function Module Addressing Number Principle 24
Chapter 8 Communication And Networking 25
8.1 Communication Port 25
8.2 Programming Environment 26
8.3 Programming Cable 26
Chapter 9 Cable Specification And Wiring 27
9.1 Connecting Power Supply Cable 27
9.2 Connecting Ground Cable 27
9.3 Connecting Common Port 28
9.4 Cable Specification 28
Chapter 10 First Operation And Maintenance 29
10.1 Notes For Application 29
10.2 Check Before Power On 29
10.3 Startup 29
10.4 RUN/STOP Switchover 29
10.4.1 How To Startup (STOP → RUN) 30


10.4.2 How To Stop (RUN → STOP) 30
10.5 Routine Maintenance 30
Chapter 11 Troubleshooting 32
Chapter 12 Instruction List 33
Chapter 13 Special Register 38
13.1 Special Intermediate Register 38
13.2 Special Data Register 42


Chapter 1 Preface 1
EC20 Series PLC User Manual
Chapter 1 Preface

Thank you for using EC20 series Programmable Logic Controller (PLC) made by Emerson Network Power Co., Ltd.
This book contains text, diagrams and explanations that will guide the reader in the correct installation and operation
of the EC20 series PLC and should be read and understood before attempting to install or use the product.
The book describes the hardware, features and applications of the EC20 series PLC, also includes the options
introduction, troubleshooting guide and instruction quick reference. For the information about how to setup an EC20
programming system and the customer programming application, please refer to ControlStar Programming Software
User Manual or EC20 series PLC Programming Manual printed by Emerson Network Power Co., Ltd. For ordering
the above user manuals, contact your Emerson distributor or sales office.
This manual is designed for the engineer who is studying, programming, installing, or servicing the EC20 series PLC.
Definitions of specific terms
PLC: Programmable Logic Controller
Main module: Refer to basic module or CPU module; it is the basic unit of the PLC. It includes master CPU, I/O ports
and power supply.
Expansion module: Generally refer to the modules except for the main module.
I/O expansion module: The expansion module for the digital signal input/output.
Special function module: Other function expansion modules except for the I/O expansion module, such as analog
signal input/output module, and busbar module.
Points: The sum of channel number of the input/output digital signal.
Digital signal: Refer to the input/output signals that only have two states: “ON” and “OFF”.
Analog signal: Continuously changed electric signal, such as 4~20mA output signal of pressure transmitter.
Unipolar signal: Generally refer to the continuously changed signal with positive polarity.
Bipolar signal: Generally refer to the continuously changed signal, which may be positive polarity or negative
polarity.
High-speed pulse: Refer to the square-wave signal with higher frequency.
Counter: Refer to the counter whose counting value increases or decreases by per pulse input according to the
increasing/decreasing control signal.
Two-phase counter: refer to the counter that has two-pulse input ports, one is for counting up, and the other is for
counting down.
AB-phase counter: refer to the counter that has two input ports of quadrature phase pulse, and counts up or down
according to the frequencies and phase differences of the two signals.



2 Chapter 2 Product Introduction
EC20 Series PLC User Manual
Chapter 2 Product Introduction
2.1 Outline
The outline of EC20 main module is shown in Figure 2-1.
123
4
5
6
7
8
9101112
13
14
15

Figure 2-1 Outline of EC20 main module
The name and function of the components in the figure are as follows:
1. The installation position of a button cell battery (CR2032 lithium battery) for data backup.
2. Power supply input ports
3. Signal input ports
4. Input signal status LEDs
5. 26pin busbar socket, used for connecting the expansion module
6. Output signal status LEDs
7. Fix screws, used for tightening the top/bottom cover of the PLC
8. Mounting holes, used for installing screws
9. Locking device of 35mm DIN, used for DIN rail installation mode.
10. Signal output ports

11. System operation status LEDs
12. Communication port COM1, providing RS485 and RS232 at the same time
13. Communication port COM0, RS232, Mini DIN8 socket
14. System operation control switch, with three positions: ON, TM and OFF.
15. Analog potentiometers (two)
2.2 Maximum Configuration
The main module and the I/O expansion modules can achieve the most 512 logic points (256 in/256 out maximum).
And eight special function modules can be expanded at most.
2.3 Internal Memory Capacity Of User Program
The user program is 8K words (16K byte) at most and supports 8,000 data blocks of D register.
2.4 Resource Configuration Of System Soft-device
Component Name Quantity Serial No. Note
X Input relay 256 X000~X377 The soft-device numbering is octal code

Y Output relay 256 Y000~Y377 The soft-device numbering is octal code

M Auxiliary relay 2000 M0~M1999
LM Local relay 64 LM0~LM63
Chapter 2 Product Introduction 3
EC20 Series PLC User Manual
Component Name Quantity Serial No. Note
SM Special auxiliary relay 256 SM0~SM255
S State relay 992 S0~ S991
T Timer 256 T0~T255
100ms precision: T0~T209
10ms precision: T210~T251
1ms precision: T252~T255
C Counter 256 C0~C255
16 bit common increasing counter: C0~C199
32 bit common decreasing counter: C200~C235

32 bit high-speed counter: C236~C255
D Data register 8000 D0~D7999
V Local data register 64 V0~V63
Z
Indexed addressing
register
16 Z0~Z15
SD Special data register 256 SD0~SD255

2.5 High-speed Input/Output Function
High-speed port
name
High-speed port type Input/output mode Max. frequency of input/output signal
X0, X1 Input High-speed pulse count
Single input: 50KHz;
X0~X5 input at the same time: frequency sum is 80KHz
X2~X5 Input High-speed pulse count Single input: 10KHz
Y0, Y1 (only suitable
for transistor output)
Output High-speed pulse output Two ports output independently: 100KHz

2.6 Filter Function Of Input Port
Function Description
Digital filter function X0~X17 provide digital filter function, and filter time is within 0~60mS, set by user’s program
Hardware filter function Other X input ports

2.7 Interrupt Source
Provide eight external interrupt inputs, the interrupt edge can be set by users and is corresponding to X0~X7 ports;
six high-speed counter interrupts; three inner timing interrupt sources.
2.8 Subroutine Call

At most 64 subroutines and 6-level subroutine nesting can be used. Support local variables and variable-alias, and
every subroutine can provide 16 parameters to be called at most.
2.9 Reinforced Debugging Function
Provide register-forced function, convenient for debugging and analyzing the user program, improving debugging
efficient. Permit the most 128 bit-registers and 16 word-registers.
2.10 Support Online Modification
Users can modify the program online during operation, which is greatly convenient for modifying and upgrading the
user program in important production situation.
4 Chapter 2 Product Introduction
EC20 Series PLC User Manual
2.11 Multiple Password Protection Function
The product provides three password authorities, which is convenient for user program access control and protecting
the intelligence property.
2.12 Expansion Module
The expansion module such as I/O module, analog signal input/output module, network expansion module, and
position control module can be connected to the PLC main module. Every module is address allocation automatically
and identification automatically.
2.13 RUN And STOP Control
RUN or STOP of the EC20 can be controlled through the following methods: the RUN/STOP switch, ControlStar
program system, communication port (i.e. Modbus), and standard input ports X0~X7, which are convenient for
controlling system operation
2.14 User Program Developing And Debugging
Provide the integrated ControlStar program system compatible with IEC61131-3 standard, and uses ladder diagram,
instruction list, and sequential function diagram to program. The unit has such functions as monitoring, debugging,
and modifying on-line. The program system also provides strong instruction guide and on-line help.
2.15 Communication And Networking
The main module has two asynchronism serial communication ports (COM1 provides RS232 and RS485 level), for
communication with personnel computer, HMI and other equipment; and the main module has an inner standard
Modbus protocol to compose 1:N network; and supports freedom protocol.
Provide Profibus module to compose the Profibus network.

Chapter 3 Installation 5
EC20 Series PLC User Manual
Chapter 3 Installation
3.1 Notes For Installation
The PLC is designed to be used in the environments meeting with standard II installation ambient, and Class 2
pollution. So the unit should be installed in such environment free of dust, conductive dust, corrosive or flammable
gas, excessive heat, moisture or rain; Besides, shocks and vibrations will also affect the reliability of the PLC and
shorten its service life, and should therefore be avoided.
Usually, the user should mount the PLC and the associated switches, contactors to the inside wall of the electric
cabinet and keep adequate natural convection. If the ambient temperature is a little high, or a heat generating
equipment is nearby, then a forced convection device should be installed on the top or the side of the cabinet to
prevent the overheat of the unit.
Take special care not to allow metal debris and wire lead to fall inside the vent of the PLC during the screw hole
processing and wiring. Otherwise there is a danger of fire, damage or faulty operation of equipment.
Once the installation of the new PLC is complete, remove everything on the surface of the vent, including packing
goods such as protective paper. Otherwise the poor ventilation during the operation may result in fire, damage or
faulty operation of equipment.
Do not wire, inset or pull out the cable plug with power applied. Otherwise there is a danger of electric shock or circuit
damage.
Installation and wiring must be firm and reliable; bad contact may result in faulty operation of equipment.
3.2 Requirements For Installation Position
To prevent a rise in temperature, mount the PLC up and down to the backboard of the cabinet horizontally. Never
mount them to the floor or ceiling of an enclosure or other directions, as shown in the Figure 3-1. You must provide a
clearance of at least 15 mm, both above and below the units, for proper cooling. No heat generating equipment

should
exist around the PLC.

Figure 3-1 Requirements for installation position
3.3 Installation Method

Generally you can mount the PLC onto a standard rail (DIN) with 35mm width. Follow these steps:
1. Fix the DIN rail to the backboard;
2. Pull out the clip (located on the bottom of the PLC) and hook the back of the PLC onto the rail.
3. Snap the clip closed, carefully checking to ensure that the clip has fastened the PLC securely onto the rail.
4. At last, install two DIN rail stops at the two sides of the PLC to avoid slippage around.
Other EC20 series modules can be mounted using the same procedures.
6 Chapter 3 Installation
EC20 Series PLC User Manual
Pull out the Clip
of DIN rail
Snap the clip of the DIN rail
DIN rail with 35mm width
DIN rail stop
DIN rail stop

Figure 3-2 Installing a PLC onto a standard rail
Under the conditions with great impact, you should mount the PLC on a panel using the screw installation. Using four
fix screws through the four Φ4 mounting holes on the enclosure of the PLC (while EC20-2012BR/BT has only two Φ4
fix screws) to fix the PLC on the back panel of the electric cabinet, as shown in the Figure 3-3.
4 mounting holes
M3 fix screw
M3 fix screw

Figure 3-2 Installing a PLC onto a panel with fix screws
3.4 Installation Dimensions
1. The dimensions for the outline and mounting holes of EC20-2012BR and EC20-2012BT are shown in the Figure
3-4:
DIN rail
(35mm)


Figure 3-4 Dimensions of outline and mounting holes of EC20-2012BR and EC20-2012BT
2. The dimensions for the outline and mounting holes of EC20-3232BR and EC20-3232BT are shown in the Figure
3-5:

Figure 3-5 Dimensions of outline and mounting holes of EC20-3232BR and EC20-3232BT
3. The dimensions for the outline and mounting holes of EC20-0808ER are shown in the Figure 3-6. And the
dimensions for the outline and mounting holes of the analog signal expansion module such as EC20-4AD, EC20-4DA,
EC20-4AM, and EC20-4TC are the same with that of EC20-0808ER.
Chapter 3 Installation 7
EC20 Series PLC User Manual

Figure 3-6 Dimensions of outline and mounting holes of EC20-0808ER and the analog signal expansion module

8 Chapter 4 Product Specifications
EC20 Series PLC User Manual
Chapter 4 Product Specifications
4.1 Model Legend
Addition (A: AC 220V input power)
D: DC 24V input power N: No power
EC 2 0 - 20 12 B R D
Output mode (R: relay; T: transistors)
Module type (B: main module; E: expansion module)
Output points
Input points
Version
Series No. (1:micro-type; 2:minitype; 3:medium-sized; 4:large-sized
Emerson PLC

Figure 4-1 Model Legend of PLC
4.2 Product Model And Configuration

4.2.1 Main Module
Table 4-1 Model and I/O configuration of EC20 series PLC,
Model
Power voltage
Vac
Input / output
points
Input signal
voltage
Output
type
Input port/
common port
Output port/
common port
Interrupt/
pulse input
Pulse
output
EC20-2012BRA 90~264 20/12 DC24V Relay 20/1 12/5 Yes No
EC20-2012BTA 90~264 20/12 DC24V Transistor 20/1 12/5 Yes Yes
EC20-3232BRA 90~264 32/32 DC24V Relay
32/1(2)
☆

32/6 Yes No
EC20-3232BTA 90~264 32/32 DC24V Transistor
32/1(2)
☆


32/6 Yes Yes

☆ “ 32/1(2)” in the table: Represent only one common port in logic, but two common ports in structure, and the two
are connected inside the PLC.
4.2.2 I/O Expansion Module
Table 4-2 I/O expansion module and configuration of EC20 series PLC
Model Power Supply Vac Input/output points Output type Inner power supply
EC20-0808ERN - 8/8 Relay No
EC20-0808ETN - 8/8 Transistor No
EC20-1616ERA 220Vac 16/16 Relay Yes
EC20-1616ETA 220Vac 16/16 Transistor Yes
EC20-1600ENN - 16/00 - No
EC20-0016ERN - 00/16 Relay No
EC20-0016ETN - 00/16 Transistor No

Chapter 4 Product Specifications 9
EC20 Series PLC User Manual
4.2.3 Special Function Module
Table 4-3 Special function module of EC20 series
Model Function
EC20-4AD 4-channel analog signal input module
EC20-4DA 4-channel analog signal output module
EC20-4TC 4-channel thermocouple temperature input module
EC20-4AM 2-channel analog signal input module, 2-channel analog signal output module

4.3 Product Size
The main modules of EC20 series PLC have the same height and width, but their lengths are related to the I/O ports.
The size of each module is listed in Table 4-4.
Table 4-4 Product size
Model Length (mm) Width (mm) Height (mm) Net weight

EC20-2012BR 158 90 82 680g
EC20-2012BT 158 90 82 680g
EC20-3232BR 227 90 82 950g
EC20-3232BT 227 90 82 880g
EC20-0808ER, 4AD, 4DA, 4AM, 4TC 58 90 82 240g

4.4 Environmental Requirements
Table 4-5 Requirements of operation, storage, and transport environments of EC20 series PLC
Environmental parameters
Type Parameter Unit
Environmental
conditions for operation
Environmental
conditions for transport
Environmental
conditions for storage
Low temperature °C -5 -40 -40
Temperature
High temperature °C 55 70 70
Humidity Relative humidity % 95 (30 ± 2°C) 95 (40 ± 2°C) /
Low pressure kPa 70 70 70
Climate
Air pressure**
High pressure kPa 106 106 106
Bit shift mm 3.5 (5-9HZ) / / Sinusoidal
vibration
acceleration M/s
2
10 (9-150HZ) / /
acceleration

spectra density
m
2
/s
3

(dB/Oct)
/
1.92 (5-20Hz) -3db
(20-200Hz)
/
Frequency range Hz / 5-200 /
Random
vibration
Vibration direction / X/Y/Z /
Type / Half-sine wave /
Impact
acceleration m/s
2
/ 180 /
Mechanical stress
Drop Drop height m / 1 /

4.5 Electric Insulation Specifications
Table 4-6 Electric insulation specifications of EC20 series PLC
Type Value Test conditions
AC input to case
≥ 5
%
10

6
Ω
AC input to DC output
≥ 5
%
10
6
Ω
Insulation
resistance
DC output to case
≥ 5
%
10
6
Ω
Ambient temperature: 25 ± 5°C; relative
humidity 90% (no condensing); test
voltage: 500Vdc
AC input to case (PG port)
AC input to the port between the user input and output
AC input to expansion busbar
User output (relay board) to expansion busbar
User input to user output (relay)
Insulation
voltage
Between user output ports (relay board)
Capable of withstanding 2830Vac/50Hz AC voltage (or
equivalent DC voltage) 1 minute, with leakage current
ñ

30mA, and no breakdown or flashover
10 Chapter 4 Product Specifications
EC20 Series PLC User Manual
Type Value Test conditions
Insulation
voltage
The insulation resistance and voltage of other circuits are designed according to the requirements of an extra-low
voltage circuit
4.6 Reliability
Table 4-7 MTBF of EC20 series PLC
Output type Time Conditions
200,000 hours Fix on the floor , mechanical stress is almost close to zero, with temperature and humidity control
Relay
100,000 hours Fix on the floor , mechanical stress is almost close to zero, without temperature and humidity control
300,000 hours Fix on the floor , mechanical stress is almost close to zero, with temperature and humidity control
Transistor
150,000 hours Fix on the floor , mechanical stress is almost close to zero, without temperature and humidity control

For the PLC with relay output, the life of its contactors is related to the load type and load capacity, as listed in Table
4-8.
Table 4-8 Use life of EC20 series output relay
Load capacity Action frequency Life-span of contactors
220Vac, 15VA, inductive load 1sec. ON / 1sec. OFF 3,200,000 times
220Vac, 30VA, inductive load 1sec. ON / 1sec. OFF 1,200,000 times
220Vac, 60VA, inductive load 1sec. ON / 1sec. OFF 300,000 times

4.7 Power Supply Specifications
4.7.1 Inner Power Supply Of Main Module
Table 4-9 Power supply circuit character of EC20 series PLCs
Item Unit Min. Typ. Max. Note

Input voltage Vac 90 220 264 Normal start and operating range
Limiting input voltage Vac 85 - 280
Operating at 280V for 3 hours and not damaged
Each circuit can power 70% rated load at 85-100Vac, and power
55% rated load at 264-280Vac
Input current A / / 1.5 90Vac input, full load output
5V/GND V 4.75 5 5.25 Output1
24V/GND

V

21.6 24 26.4 Output2
Output
voltage
24V/COM

V

21.6 24 26.4 Output3
5V/GND mA 1000
24V/GND

mA 650
Output
rated
current
24V/COM

mA 600
The capacity is the sum of the main module inner consumption

and the expansion module load. The maximum output power is
35W, which is the sum of each circuit output with full load. The
module is natural cooling

4.7.2 Use Of Each Circuit Output Power
1. Output1 (5V/GND): Output1 is the working power of the PLC main module logic circuit, and provides power supply
to the expansion module logic circuit through the expansion port of the module at the same time. And this power will
not be used for the expansion module with self-carried power source.
2. Output2 (24V/GND): Output2 is the working power of the PLC main module relay output circuit, and provides
power supply to the expansion module relay output circuit through the expansion port of the module at the same time.
Output1 and output2 share the common ground. And this power will not be used for the expansion module with
self-carried power source.
3. Output3 (24V/COM): Output3 is the 24V power supply, which is provided to users by the PLC main module. Also it
can be used as an auxiliary power to other user circuits, sensors or expansion modules through the “24V” and “COM”
ports of the main module. Output3 is electrical isolated with Output1 and Output2.
Chapter 4 Product Specifications 11
EC20 Series PLC User Manual
4.7.3 Power Specifications Provided By Main Module To Expansion Module
Table 4-10 Power capacity consumption and load current provided
Logic circuit power supply Auxiliary power supply output
5V/GND 24V/GND 24V/COM
Model
Inner
consumption*
Capacity
provided*
Inner
consumption
Capacity
provided

Inner consumption Capacity provided
EC20-2012BR 250mA 750 mA 70 mA 580 mA
EC20-2012BT 400 mA 600 mA 0 650 mA
140mA 460 mA
EC20-3232BR 480 mA 520 mA 240 mA 410 mA
EC20-3232BT 650 mA 350 mA 0 650 mA
240mA 360 mA

*Explanation:
The current of “Inner consumption” in Table 4-10 is the average current consumed when the module inner circuit
works. Users cannot change it directly.
The current of “capacity provided” in Table 4-10 is the part capacity of the main module that can be used for the
external control module. The data listed in Table 4-10 is under the stable ambient condition with 25°C. If input voltage
is out of rated voltage range or the working temperature exceeds +50°C, users should consider the derating design,
which is mainly obtained by decreasing the value of “capacity provided”, to ensure the reliable operation of the PLC.
4.7.4 Derating Design Of Power Supply Circuit
1. Relation between power supply output capacity derating and power supply input voltage
When the input voltage of the PLC is beyond the rated voltage range, users should consider decreasing the main
module’s output power to the expansion module. The derating relation is shown in Figure 4-2.
Power load %

Input voltage Vac



85
Vac
100
Vac
264

Vac
280
Vac

Figure 4-2 Derating curves of power supply output capacity and power supply input voltage
2. Power output capacity derating vs. work temperature relationship
When the work temperature is higher than the upper limit of the specification, the power capacity provided (including
5V/24V/GND and 24V/COM) by the main module to the expansion module must be derating. The derating relation is
shown in Figure 4-3.
Power load %
Operation ambient
temperature

°C

-5°C
50°C
55°C

Figure 4-3 Derating curve between power output capacity and work temperature
12 Chapter 4 Product Specifications
EC20 Series PLC User Manual
4.7.5 Power Consumption Of Expansion Module
Table 4-11 Power consumption of each expansion module
Max. current consumption
Model
5V/GND 24V/GND 24V/COM
EC20-0808ER 30mA 50mA 50mA
EC20-0808ET 80mA 0 50mA
EC20-4AD 50mA 0 25mA

EC20-4DA 50mA 0
120mA
☆

EC20-4AM 50mA 0
90mA
☆

EC20-4TC 50mA 0 25mA

☆: Refer to the power consumption when the analog output channel port connects with the output. If the current
output port (0~20mA) is not used, the current can be decreased to 50mA.
4.7.6 Power Capacity Calculation In Expansion Connection
Before the PLC connects with an expansion module, users should calculate the current sum of each power supply of
the expansion module, and ensure the current sum is less than the output current provided by the corresponding
power supply of the main module to avoids the over loading of the main module power supply.
Example 1: the main module is EC20-2012BR, at 25°C ambient temperature, two EC20-0808ET, two EC20-4AD,
one EC20-4DA and one EC20-4TC shall be connected to, verifying the feasibility.
Checking computations as following:
Power circuit Current provided by the main module Actual consumed current conclusion
5V/GND 750mA (80×2+50×2+50+50) = 360mA Pass
24V/GND 580mA (0×2+0×2+0+0) =0 mA Pass
24V/COM 460mA (50×2+25×2+110+25) = 285mA Pass

It is obvious that the total power consumption of above expansion module is less than the permission load of the main
module, and the designing scheme is feasible.
Example 2: the main module is EC20-3232BT, at 25°C ambient temperature, three EC20-0808ET, two EC20-4AD,
one EC20-4DA shall be connected to, using 20mA output port and one EC20-4TC.
Checking computations as following:
Power circuit Current provided by the main module Actual consumed current conclusion

5V/GND 350mA (80×3+50×2+50+50)=440mA Un-passed
24V/GND 650mA (50×3+0×2+0+0)=150mA Pass
24V/COM 360mA (50×3+25×2+120+25)=345mA Pass

The sum of the 5V/GND power consumption of the expansion module is 440mA, it is larger than 350mA which is the
upper limit of 5V power supply; although the power consumption of 24V/GND and 24V/COM is less than the
permitted current of the main module, the designing scheme is unfeasible.
The solution to solve the insufficient of power supply capacity is to select the expansion module with self-carried
power source. It can power by itself, also its outputs of 5Vdc/GND, 24Vdc/GND, and 24Vdc/COM can power to the
expansion module added later.
4.8 Programming Tool Of User Program
ControlStar programming system provides the programming, up/down-loading, debugging and monitoring the user
program of the EC20 series PLC. The system also provides abundant help information, which can use ladder
diagram, instruction list and sequence functional diagram to program.

Chapter 5 Input Characteristic 13
EC20 Series PLC User Manual
Chapter 5 Input Characteristic
5.1 User Ports Of Main Module
The outline and the ports of EC20-2012BR and EC20-2012BT are the same. Their port wirings are shown in Figure
5-1:
PG COM X0 X2 X4 X6 X10 X12 X14 X16 X20 X22
LX1X3X5X7 X21X11X13X15X17 X23
N

Wiring of EC20-2012BR and EC20-2012BT

+24V
Y0
Y2 Y4 Y6 Y10 Y12

Y1
Y13Y5 Y7 Y11COM
COM
0
COM
1
COM
2
Y3
COM
3
COM
4

Figure 5-1 The outline and the port of EC20-2012BR and EC20-2012BT
The pin definitions of EC20-2012BR and EC20-2012BT are listed in Table 5-1:
Table 5-1 Pin functions of EC20-2012BR and EC20-2012BT
Pin Function Note
L/N 220Vac AC power input port, L is live line, N is neutral line
PG Earth port
●

Null port, used for isolation and not wiring
X0~X23 User input signal ports, used together with COM can produce input signal
COM
Common port, it is the negative pole of the +24Vdc auxiliary power and the
common port of input as well. Two COMs connect inside the PLC

+24V The auxiliary power to user external equipment , used together with COM
Y0, COM0 Control output port, group 0

Y1, COM1 Control output port, group 1
Y2, Y3, COM2 Control output port, group 2
Y4~Y7, COM3 Control output port, group 3
Y10~Y13, COM4 Control output port, group 4
The COMx (COM0 ~
COM4) of each output
group are electrical
isolated one another

The outline, port layout and function definition of EC20-3232BR and EC20-3232BT are the same. The port layout is
shown in Figure 5-2:
14 Chapter 5 Input Characteristic
EC20 Series PLC User Manual
PG COM X0 X2 X4 X6 X10 X12 X14 X16 X20
LX1X3X5X7 X21X11 X13 X15 X17
+24V
N
X24
X23 X33 X37
X22
COM
X25 X27 X31
X26 X30 X32 X34 X36
X35

Wiring of EC20-3232BR and EC20-3232BT

Y0
COM
2

Y5 Y7 Y11 Y13 Y15 Y17 Y21
Y6 Y12 Y22Y14 Y16 Y20
COM
3
Y25
Y24 Y34
Y23
Y3
Y26 Y30 Y32
Y27 Y31 Y33 Y35 Y37
Y36
Y1
COM
0
COM
1
Y2 Y4 Y10
COM
4
COM
5

Figure 5-2 Outline and port layout of EC20-3232BR and EC20-3232BT
Table 5-2 Pin definition
Pin Function Note
L/N 220Vac AC power input port, L is live line, N is neutral line
PG Earth port
●

Null port, used for isolation and not wiring

X0~X37 User input signal ports, used together with COM can produce input signal
COM
Common port, it is the negative pole of the +24Vdc auxiliary power and the
common port of input as well. Two COMs connect inside the PLC.

+24V The auxiliary power to user external equipment , used together with COM.
Y0, COM0 Control output port, group 0
Y1, COM1 Control output port, group 1
Y2~Y7, COM2 Control output port, group 2
Y10~Y17, COM3 Control output port, group 3
Y20~Y27, COM4 Control output port, group 4
Y30~Y37, COM5 Control output port, group 5
The COMx
(COM0~COM4) of
each output group are
electrical isolated one
aother.

5.2 Input Port Characteristic And Signal Specification
Table 5-3 Input port characteristic and signal specification
Item High-speed input port X0~X7 General input port
Signal input mode Leak mode, users only need to connect dry contact with Xn and COM ports.
Test voltage 24Vdc
Input impedance 3.3k 4.3k
Input ON External circuit resistance < 400Ω
Electric
parameters
Electric
parameters
Input OFF External circuit resistance > 24kΩ

Digital filter X0~X17 have digital filtering function, the filtering time can be set within 0~60ms Filtering
function
Hardware filter Except for X0~X17, other I/O ports are hardware filtering, filtering time is about 8mS.
High-speed function
X0~X7 have high-speed counting, interrupt, and pulse catching function.
The highest counting frequency of X0 and X1 port is high up to 50KHz
The highest counting frequency of X2~X5 port is high up to 10KHz
Input Only has one common port: COM
Common port
Output Have multi isolated common ports according to different point configuration.

Chapter 5 Input Characteristic 15
EC20 Series PLC User Manual
5.3 Inner Equivalent Circuit Of Input Port
There is a user switch status detecting power supply (24Vdc). Users only need to connect to the switching signal of
the dry contact. If the output signal of active transistor sensor is connected to, an OC output signal is needed. Figure
5-3 shows the signal input and inner equivalent circuit of the PLC, and user’s circuit connects with PLC inner circuit
through the connecting port.
24Vdc auxiliary
power supply
Logic processing circuit
Working power for
inner logic circuit
24V+
24V -
24V+
COM
X0
X1
X2

Xn
Sensor
User signal wiring
Inner equivalent circuit of PLC main module
24V/5V/GNG
Various signal input equipment

Figure 5-3 Inner equivalent input circuit of the main module (upon delivery)
As shown in Figure 5-3, the external signal input is “a SINK input”. You may need “a SOURCE input” in some special
application, and you can change the soldering of the three jumper terminals of JP0, JP1, and jp2 on the interface
board inside the PLC to reset the input mode, according to the screen-printing on the board (“ ” represents soldering;
“×”represents disconnection). As shown in Table 5-4:
Table 5-4 Screen print illustration
JP0 JP1 JP2
Source input mode


%

%

Drain input mode (default setting)
%






The equivalent input circuit changed to the SOURCE input mode is as Figure 5-4:

COM
X2
24V-
X0
Xn
24V+
24V+
X1
User signal wiring
24Vdc auxiliary
power supply
Working power for
inner logic circuit
24V/5V/GND
Logic processing circuit
Various signal input equipment
Inner equivalent circuit of SOURCE input mode of the main module
For equipment with self-carried
power source (24Vdc)

Figure 5-4 inner equivalent circuit of SOURCE input mode of the main module
16 Chapter 5 Input Characteristic
EC20 Series PLC User Manual
Note: in the main module, all the input ports can but use the same input mode (SOURCE input mode or SINK input
mode); if you have any requirement, please contact your supplier and ask for the technical support before purchasing
the product. To avoid damage, you’d better not change the circuit by yourself.
The inner equivalent power supply and input signal connection of the I/O expansion module are shown in Figure 5-5:
Logic circuit
Provided by
extension cable

To 24V+ of main module
To COM of main module
X0
X1
X2
Xn
Sensor
Signal input equipment
User signal wiring
Internal equivalent circuit of the
PLC extension module
Power supply of logic
circuit : 24V/5V/GND
24V+

Figure 5-5 Inner equivalent input circuit of the I/O expansion module
5.4 Input Connection Of High-speed Counter
Table 5-5 the counter connection method and characteristic realized by X0~X7
Counter

Input point
X0 X000 X001 X002 X003 X004 X005 X006 X007
Max. Fre.
(KHz)
Counter C236 Up/down 50
Counter C237 Up / down 50
Counter C238 Up / down
Counter C239 Up / down
Counter C240 Up / down
Counter C241 Up / down

Counter C242 Up/down Reset
Counter C243 Up / down Up / down
Counter C244 Up/down Reset Reset
Single-phase
single-end
count input
mode
Counter C245 Up / down Up / down Reset
10
Counter C246 Up Down 50
Counter C247 Up Down Reset
Counter C248 Up Down Reset
Counter C249 Up Down Reset Start
Single-phase
up/down
count input
Counter C250 Up Down Reset Start
10
Counter C251 Phase A Phase B 30
Counter C252 Phase A Phase B Reset
Counter C253 Phase A Phase B Reset
Counter C254 Phase A Phase B Reset Start
Two-phase
up/down
count input
Counter C255 Phase A Phase B Reset Start
5

Among which:
Phase A: phase-A input port of the two-phase counter;

Phase B: phase-B input port of the two-phase counter.
Chapter 5 Input Characteristic 17
EC20 Series PLC User Manual
5.5 Interrupt Input Connection
For the system that responds promptly to the input signal, it can use the interrupt to process the signals. The input
ports of X0~X7 have interrupt function and corresponds to the eight external interrupt sources.
If the input port is used as interrupt process mode, the corresponding interrupt control identification should be
enabled when programming and the corresponding interrupt routine should be programmed (for details, refer to
Programming Reference Manual). When using interrupt, the digital filter function of corresponding X port will be
disabled and the filter time of the corresponding port is set as zero automatically.
z When used as high-speed count input or interrupt input, the corresponding input port should use shielding wire,
and the shielding wire should connect to earth line (same as PG port) to improve the interference rejection.
z Some counters require multiple X input ports to realize (for example, C242, C244, and C254 consist of 2, 3, 4
ports separately). After using this kind of counter, the used ports cannot be used as input of other counters and
the common input mode.
z The input port of the counter has the limitation for the maximum frequency. Beyond the limitation, it may result
the incorrect counting or normal operation of the system. You should use the input port reasonable and select
the suitable external sensors.
5.6 Input Signal Status Indication
The input status LEDs indicate the status of the user input port. When the input port is closed (“ON” state), the LED is
on; otherwise the LED is off. When the X0~X7 ports input high frequency signal, the flashing frequency of the LED
may be lower than that of the actual input signal, which is for the convenience of the user to observe the
characteristics of the port signals.
Output terminal status LEDs
Working status LEDs Input terminal status LEDs

Figure 5-6 Status LEDs of EC20 series main module
5.7 Analog Potentiometer And Application
The analog potentiometer provides external channel for users setting inner soft-device, which is within 0~255 and
read by user program.

When adjusting the setting value, users can use a small Philips screwdriver to rotate the potentiometer clockwise to
increase the setting value, and counter clockwise to decrease it. The maximum angle of rotation is 270°. Do not
energize excess.
5.8 Example Of Input Connection
Figure 5-7 shows an example: an EC20-3232BT connects with an EC20-0808ER to realize a simple position control.
The high-speed counting ports of X0 and X1 detect the position signal from the encoder. The high-speed ports of
X3~X7 connect to the travel switch which needs quickly response, other user signals can be distributed with input
ports.
18 Chapter 5 Input Characteristic
EC20 Series PLC User Manual
L
PG
N
24V COM
AC-L
AC-N
X0 X1
+24V
+5V
GND
EC20-3232BT
0808ER
XmXn
24V
X3X2 X5X4 XmXn
Sensor
X7X6 X11X10 X36 X37
A
B
Z

+24V
VGND
PG
Switch power
supply
Using terminal block connects to COM

Figure 5-7 electric connection of EC20-3232BT and EC20-0808ER

Chapter 6 Output Characteristic 19
EC20 Series PLC User Manual
Chapter 6 Output Characteristic
6.1 Output Port Application
1. The output type of EC20 series PLC can be divided into relay type and transistor type. Both types are greatly
different in the operation parameters. You should distinguish the difference before using them to avoid the damage by
the misuse.
2. To protect the contacts of the PLC output relay, when the drive DC circuit is inductive (such as relay coil), a
fly-wheel diode shall be connected to the user circuit; when the drive AC circuit is inductive, a RC surge absorber
shall parallel connect to the user circuit. In principle, the relay output port does not connect to the capacitive load. If
there is necessary to use, its surge current must be less than the maximum current in the specification list (see Table
6-1).
3. The transistor output port should be within the limitation of the allowable maximum current (see Table 6-1) to
ensure the thermal value of the output port is limited in the allowable range. If output currents of multiple transistors
are bigger than 100mA, they should be distributed equally in the output ports. Distributed adjacent will affect the heat
dissipation.
4. It is recommended the output points which are in the ON (conducting) state at one time shall not exceed 60% total
output points for a long time.
Table 6-1 Comparison of relay output and transistor output
Item Relay output Transistor output
Output

action
Dry contact output, output state is “ON” (conducting) , contacts are closed; output state is ”OFF”, contacts are open.
Common
port
Divided into multiple groups, each group has a common port COMn, suitable for the control circuit with different
potential, and all common ports are insulated one another.
Voltage 220Vac; 24Vdc, no polarity requirement 24Vdc, polarity requirement
Current Accord with output electric specifications (see Table 6-2)
Difference High drive voltage, high current Low drive current, high frequency, long lifespan
Application
To drive the load with low action frequency such
as: intermediate relay, contactor coil, and LEDs
To apply in the situation with high frequency and long life, such as
control servoamplifier and electromagnet with frequent action

6.2 Electric Specifications Of Output Port
Table 6-2 Electric specifications of output port
Item Relay output port Transistor output port
Loop power supply voltage Below 250Vac, 30Vdc 5~24 Vdc
Output current
Single point: 2.0A /250Vac
The total current of the 8 points
sharing COM port is less than 8A.
0.5A 24Vdc
The total current of the 8 points sharing COM port is less than
2A.
Circuit insulation mechanical insulation Optical coupling insulation
Act indication
Relay output contacts closed, LED
on

Optical coupling is driving, LED on
Leakage current at open
circuit
- Less than 0.1mA/30Vdc
Min. load 2mA/5Vdc 5mA (5~24Vdc)