Cypress Duprex

Cypress Duprex 

Dual Reader Supervised Extender 

Wiring Diagram and Operators Manual 

MAN-FA-DPX-7000 V1.07 

©2005 Cypress Computer Systems,Inc. • www.cypressworld.com 11/21/05 Page 1

Table of Contents 

Quick Reference guides Page 3 

General specifications, Dip switch settings Page 5 

Electrical specifications, Introduction Page 6 

Status indicators and Dip switch details Page 7 

Identification of major components Page 8 

Detailed terminal connections Page 9 

Power connection Page 11 

Communication connections Page 14 

Reader data connections Page 15 

Door strike relay Page 18 

Alternate I/O SW #5 ON, Strike and Alarm Relays Page 19,20 

Auxiliary inputs and outputs Page 21 

Supervised contacts and programming resistors Page 25 - 28 

Part numbers for different versions: 

DPX-7000: RS-485 Twisted pair 

DPX-7500: RS-232 wired 

DPX-5000 Series *: Duprex RF 900 MHz 

DPX-5100 Series *: Duprex RF, 900 MHz, extended temperature range 

DPX-5200 Series *: Duprex RF, 2.4 GHz 

DPX-7200 Series *: Duprex Ethernet 

DPX-7400 Series *: Duprex Fiber Optic 

* supplemental installation manuals available 


Connector Terminal Identification- Quick Reference 

Panel /Port # 1 Signals 

Alarm Programming Resistor 

Aux #3 Programming Resistor 

Aux Digital I/O #1 Input 

Aux Digital I/O #2 Output 


Alarm Relay N.O. 

Alarm Relay Com 

Alarm Relay N.C. 

LED 

Data 1 /Data 

Data 0 /Clock 

+5 VDC 

Ground 

+8 - 24 VDC 

Reader # 1 Signals 

Alarm Digital Input 




N/C 

Strike Relay N.O 

Strike Relay Com 

Strike Relay N.C. 

LED 

Data 1 /Data 

Data 0 /Clock 

+5 VDC 

Ground 

+8 - 24 VDC 

Line - 

Line + 

Line - 

Line + 

+8 - 24 VDC 

+8 - 24 VDC 




Strike Relay N.O. 

N/C 





©2005 Cypress Computer Systems,Inc. • www.cypressworld.com 11/21/05 Page 3 

Gnd 

C 

Duprex Central Unit 

Gnd 

R 

Duprex Remote Unit 

Panel/Port # 2 Signals 

+8 - 24 VDC 

Ground 

+5 VDC 

Data 0 /Clock 

Data 1 /Data 

LED 

Alarm Relay N.C 


Alarm Relay N.O 






+8 - 24 VDC 

Ground 

+5 VDC 

Data 0 /Clock 

Data 1 /Data 

LED

1 2 3 4 5 6 7 8 

DIP Switch Settings- Quick Reference 

NOT USED 

ALL OFF 

On 

Off 

Wiegand 

Wiegand / No Filter 

Strobed Rising Edge (MR-5) 

Strobed Rising Edge (Dorado 644) 

Strobed Rising (Mag-Tek) 

Strobed Falling Edge 

Reserved 

Reserved 

1 2 3 4 5 6 7 8 

Switch 

6 7 8 

0 

1 x 

2 x 

3 x x 

4 x 

5 x x 

6 x x 

7 x x x 

x = ON 

CENTRAL UNIT ONLY 

Dip switch #5 is ON 

Alternate I/O Assignment 

a. Door Strike relay does NOT follow LED 

(Auxiliary setting, will follow Digital Input #1) 

b. Alarm Relay and Digital Output #3 swap 

functions. 

All settings except Switch 5 are the same for Central and Remote units. 


General Description and specifications: 

The Cypress Duprex series DPX-7000 is the latest addition to the Suprex line of products. 

For those familiar with the Cypress Suprex series, a DPX-7000 can be considered as 2, SPX-2000 

units in one package that share the same communication channel. 

The DPX-7000 will connect up to 2 readers to 2 panels using 1 pair of wires. There is also the ability to 

send additional signals such as Request to Exit, Tamper, Alarm, and Door contacts with each reader 

port. 

A DPX-7000 system consists of a pair of units. A Central unit connects to the Access Control Panel and 

a Remote unit connects to the Badge reader and door/ gate hardware. The reader data and status 

signals are sent over a single pair of wires up to 10,000 feet . Modules are available for Radio (RF), 

Fiber optic, and Ethernet data links. 

The DPX-7000 series has the ability to be field configured for various reader formats. 

The DPX-7000 series has also eliminated the need for “Pullup” resistors in most installations. 

Suprex Remote Unit Dip Switch Settings 

All Off except 6,7,8 (see below for details) 

Suprex Central Unit Dip Switch Settings 

Switch #5- On = Alternate I/O Assignment: 

Strike relay does NOT follow LED , will follow Digital Input #1 

Alarm relay and Digital Output #3 exchange functions. 

Off = (Default) Normal operation. Strike follows LED status. 

Dip Switch Settings 6.7.8 for Central AND Remote 

Switches 6,7,8 select the type of reader format used. 

Mode 0. 6,7,8 OFF = Standard Wiegand 

Mode 1. 6,7 OFF ; 8 ON = Wiegand without filtering 

Mode 2. 6 OFF, 7 ON, 8 OFF = Strobed, rising edge trigger, (MR-5® Compatible) 

Mode 3. 6 OFF, 7 ON, 8 ON = Strobed, rising edge trigger, (Dorado 644® compatible) 

Mode 4. 6 ON, 7 OFF, 8 OFF = Strobed,rising edge trigger, (Mag-Tek® compatible) 

Mode 5 6 ON, 7 OFF, 8 ON = Strobed, falling edge trigger 


Specifications: 

Voltage- 8 to 24 VDC OR + 5VDC 

Current- 100 mA nominal 

Range: Up to 10,000 feet for RS-485 versions 

May vary due to quality of wiring. Any isolated wire pair will function 

with possible degraded performance. 

Optimal wiring is shielded twisted pair of 22 ga. or better. 

Relay Contact Rating- 2A @ 125 VAC 

Digital Input Rating: 0 to + 5 Volts DC standard CMOS logic levels 

Digital Output Rating: 25 mA Sink 0.5 mA source (10k pullup resistor) 

Initial Installation 

Before installing the units in the field, it is a good idea to connect and apply power to the units 

on a bench before installation in the field location. This is especially recommended if there is 

unfamiliarity with the Suprex/Duprex series of products. By initially connecting and powering up the 

units together, the operation can be observed on both the Central and Remote. Wiring configuration 

and connections can be verified, and any potential problems can be solved much easier than if the 

units are separated by several thousand feet. 

We recommend that the installation proceed in the following order: 

1. Unpackage the units and visually inspect for any shipping damage. 

2. Using a power supply or access control panel, apply power to both units using the same power 

configuration that will be utilized in the final installation. 

3. Connect communication lines RS485 (+) and RS485 ( -) between the Central and Remote. 

4. Check LED indicators for normal operation. With the communication lines connected, the yellow 

led should flash rapidly and the diagnostic led should flash on and off about once per second. The 

green power LED should be illuminated steady. 

5. Check/ Set the dip switch on Central and Remote units for the type of reader data format that will be 

used. 

6. If a reader and panel are available , connect the reader to the Remote unit and connect the Central 

unit to the panel. Using a test badge, verify that the panel can receive badge reads from the reader, 

and that the Strike / LED signals are operating in the expected manner. 

7. Install the units in their final locations. 


Indicators: 

Each duprex unit is equipped with 3 leds to convey the operational status of the unit. 

Green power LED: 

This led will illuminate a continuous green color when power is applied to the unit. If this led is 

not illuminated, power has been lost to the unit. 

Amber communication LED: 

The communication LED indicates the actual communication activity between the Central and 

Remote unit. The LED will flash rapidly (about 5 times per second) when the Central and 

Remote units are communicating. 

When communication is lost the Amber LED will flash slower at about 1-2 times per second. 

BiColor diagnostic LED: 

This led will indicate basic status of the units. If the units are not in communication with each 

other the diagnostic LED will light a solid red color. When the units are able to communicate with 

each other, the diagnostic LED will flash green on and off about once per second. 

DIP Switch Settings: 

INDICATORS AND SETTINGS 

The Cypress Duprex supports multiple reader data formats. Each data format can be set with 

the dip switch. The dip switch format will be read each time the unit powers up. 

Mode 0 . Wiegand mode: Supports Wiegand data 24 to 248 bits. This mode will filter out data 

(noise) of less than 24 bits. This mode WILL allow keypad data of 4 and 8 bit burst mode 

Wiegand to pass. 

Mode 1. Wiegand mode without filter: This mode permits all Wiegand bits to be read without 

applying a noise filter. Any number of Wiegand bits from 4 to 248 will pass in this mode. Use 

this mode to support equipment that uses a nonstandard number of bits that number less than 

24 bits. 

Mode 2. Strobed data mode, Rising edge trigger. Mercury® MR-5 reader emulation. 

Mode 3. Strobed data mode, Rising edge trigger. Dorado® 644 reader emulation. 

Mode 4. Strobed data mode, Rising edge trigger. Mag-Tek® reader emulation 

Mode 5. Strobed data mode, Falling edge trigger. For all readers that trigger data on the falling 

clock edge. 


The Cypress Duprex System consists of a Central and a Remote unit. Each Duprex board has 

connections for 2 reader channels. The Remote board has connections for 2 readers, the 

Central board has connections for 2 Panels or ports on multi reader panels. 

The Central and Remote are physically alike and will be identified by a sticker or permanent 

label with a large “C” or “Central” label and a large “R” or “Remote” label. Each reader/panel 

combination operates as a separate and independent channel. 

The reader connectors are identified by their relative location on the circuit board in relation to 

major components. 

Reader Number 1 

Signal connections 

to and from Panel 


Data to Panel 


Data from Reader 

{ 

{ 

Configuratio 

n 

Dip Switch 

{ 

{ 

Identification of major components 


C 

Central Unit 

Diagnostic LED (Red/Green/Yellow multi color) 



to and from access 

control devices. 

Strike Relays 

R 

Remote Unit 

Communication and 

power connector 

Alarm Relays 

{ 

{ 

Communication 

Activity LED 

(Amber) 

{ 

{ 


Data to Panel 



to and from Panel 


Data from Reader 


Signal 

connections 

to and from 

access control 

devices. 

Power LED (Green)

Connector Terminal Identification- Central unit 

C 

Panel /Port # 1 Signals 






Alarm Relay N.O. 


Alarm Relay N.C. 

LED 

Data 1 /Data 

Data 0 /Clock 

+5 VDC 

Ground 

+8 - 24 VDC 

Panel/Port # 2 Signals 

+8 - 24 VDC 

Ground 

+5 VDC 

Data 0 /Clock 

Data 1 /Data 

LED 

Alarm Relay N.C 


Alarm Relay N.O 






C 


Connector Terminal Identification- Remote unit 

R 






N/C 

Strike Relay N.O 



LED 

Data 1 /Data 

Data 0 /Clock 

+5 VDC 

Ground 

+8 - 24 VDC 


+8 - 24 VDC 

Ground 

+5 VDC 

Data 0 /Clock 

Data 1 /Data 

LED 



Strike Relay N.O. 

N/C 





R 


Supplying Power: 

There are several ways to supply power to the Duprex units. Each of these will be 

discussed in detail. 

The 4 Wire method is used when there is only one power supply and the distance between the two 

units is not very large. 

A. The “4 Wire” method. This method uses one supply to power both the Central and 

Remote units. It requires 4 wires to connect the two units together. NOTE: The +8 to 24V connections 

on the reader interface connectors and the 4 position communication connector are electrically the 

same. 

The power supply can be located at either the Central or Remote unit. However, only one power 

supply should be used for this configuration. The power supply can be connected to the reader 

interface or the 4 position communication connector. 

Reader interface 

connector 

Gnd 

+V 

Line - 

Line + 

Communication Connector 

Power Supply 

+8 to 24 VDC 

Reader interface connector 


C 

R 

+V 

Gnd


B. The “2 Wire” method. This method uses two power supplies. One to power the Central and the 

other to power the Remote unit. It requires 2 wires to connect the two units together. NOTE: The +8 

to 24V connections on the reader interface connectors and the 4 position communication connector 

are electrically the same. 

The power supplies are located at both the Central and Remote unit. The power supplies can be 

connected to either the reader interface or the 4 position communication connector. The illustration 

shows connection to reader interface connectors. Either the Reader 1 or Reader 2 connector can be 

used to connect the power supply. 

Warning: If connecting the Duprex Central unit to two separate panels or reader ports, do not supply 

power to the Duprex unit from more than ONE panel or one port. If using a panel to supply power, 

connect power from one panel and only connect the signal ground on the other panel. Connecting 

multiple power supplies can result in unpredictable operation or failure of the power supplies. 

Reader 1 

connector 

Line - 

Line + 

Power Supply 

+8 to 24 VDC 

Power Supply 

+8 to 24 VDC 


C 

R 

+V 

Gnd 

Reader 2 

connector


C. The “2 Wire 5 Volt” method. This method also uses two supplies. One to power the Central and 

the other to power the Remote unit. It also requires 2 wires to connect the units together. This 

method is used when the only power available is an existing 

5 volt supply. It is not recommended to use one 5 volt supply to power both units. 

The power supplies are located at both the Central and Remote unit. The 5 volt power must be 

connected to the reader interface + 5 Volt and Ground connections. The other unit can be supplied 

by either a 5 volt or 8 to 24 volt supply. 

Note: When using the 5 Volt power connection, make sure that only one power supply is connected to 

each unit. The +8 to 24 and 5 Volt supplies should NEVER be connected or used at the same time. 

Illustration shows both units with 5 volt power supply. 

Reader 1 

connector 

Line - 

Line + 

C 

R 

Power Supply 

+5 VDC 

Reader 2 

connector 

Power Supply 

+5 VDC 


Gnd 

+5V 

Gnd 

+5V

Communication Connections and initial power application: 

The examples shown in the power connection methods also indicated how the RS-485 

communication lines are connected. Shown below is a typical connection for a Duprex Remote 

and Central unit using one of the power connection diagrams. 

With the units connected using A,B, or C power connections, turn on the power supply. Only power 

and communications connections should be made at this point. 

Data and I/O connections should be made after power and communication is verified. 

Regardless of which connection method is used, a correctly wired and operating setup will have 

these indications: 

a. The Green power indicator will be illuminated. 

b. The Amber communication indicators will be flashing rapidly on both Central and Remote units. 

c. The Diagnostic indicator will flash Green on and off at about once per second. 

Do not proceed further if this is not the case. Refer to the troubleshooting guide to correct any 

problems. 

Diagnostic 

indicators 

Gnd 

+V 

Line - 

Line + 

C 

Communication 

Active 

R 

Communication 

Active 

Power Supply 

+8 to 24 VDC 

Green Power 

indicator 


Reader Data Connections: 

The diagrams below show data connections for the reader signals. Power and communication 

connections are still present, but have been removed from the diagram for clarity. 

A Duprex will support 2 reader data channels. The reader data channels operate separate and 

independent from each other. The Duprex can be wired with either reader port or both readers. 

It is important to remember that a reader on the Remote port 1 will output its data on the Central port 1 

and the Remote port 2 will output its data on the Central port 2. If no reader data is being observed at 

the panel, verify that the correct reader connections have been made and that the panel is connected to 

the correct port. 

Warning: If connecting the Duprex Central unit to two separate panels or reader ports, do not supply 

power to the Duprex unit from more than ONE panel or one port. If using a panel to supply power, 

connect power from one panel and only connect the signal ground on the other panel. Connecting 

multiple power supplies can result in unpredictable operation or failure of the power supplies. 

The DPX-7000 has eliminated the need for “Pullup” resistors in most installations. 

Control Panel 

Reader Port 

Number 1 

Card Reader 

Port Number 1 

Central 

Unit 

C 

R 

Remote 

Unit 

Control Panel 

Reader Port 

Number 2 

Card Reader 

Port Number 2 


Detailed Reader Port Connections- Central unit 

Power supply connections are not shown for clarity. 

C 

Panel / Port # 1 Signals 

LED 

Data 1 /Data 

Data 0 /Clock 

Ground 

Panel / Port # 2 Signals 

Ground 

Data 0 /Clock 

Data 1 /Data 

LED 

C 

1 2 3 4 5 6 7 8 


Detailed Reader Port Connections- Remote unit 

Power supply connections not shown to clarify data connections. 

R 


LED 

Data 1 /Data 

Data 0 /Clock 

+5 VDC 

Ground 

+ 8 to 24 VDC 


+ 8 to 24 VDC 

Ground 

+5 VDC 

Data 0 /Clock 

Data 1 /Data 

LED 

R 

1 2 3 4 5 6 7 8 


Door Strike Relay connection and operation: 

In the standard configuration, the door strike relay on the Remote is activated when the LED 

signal is triggered on the Central unit. When the Central unit LED input is connected 

electrically to Ground ( 0 volt reference) it will trigger the LED output and Strike relay on the 

Remote unit. 

The dip switch on the Central unit can set two different modes for triggering the Door Strike. 

Interface #1LED 

signal from panel 

activates LED and 

Door Strike on 

Remote reader #1. 

Dip switch #5 is OFF 

Door Strike relay follows LED 

(Standard setting) 

1 2 3 4 5 6 7 8 

Door Strike Contacts 

Reader interface #1 

Door Strike Contacts Reader interface #2 

N.O. Contact 


Common 

N.C. Contact 

N.C. Contact 

Common 

N.O. Contact 

Remote Unit 


C 

Central Unit 

R 

Interface #2LED 

signal from panel 

activates LED and 

Door Strike on 

Remote reader #1.

Door Strike Relay Alternate I/O Setting: 

In the Alternate I/O configuration, the door strike relay on the Remote is activated when the 

Auxiliary digital input signal is triggered on the Central unit. The Central unit LED input will only 

trigger the LED output on the Remote unit. 

When the auxiliary digital input #1 on the Central unit is activated (Grounded), the Door Strike 

Relay on the Remote unit will operate. This will operate in this manner as long as DIP switch #5 is 

set to ON at the Central unit. 

There is an auxiliary digital output on the Remote unit. This is a 0 to 5 volt digital output that 

always follows the Auxiliary digital input on the Central unit, regardless of the switch #5 setting. It 

can be used as an additional low power driver or I/O control. See Auxiliary inputs and outputs for 

details. 


Auxiliary Digital I/O 

#1 Input 

triggers Strike Relay 

LED signal from panel 

only activates LED on 

Remote 



Auxiliary Digital output #1 

follows Aux input on 

Central 

N.O. Contact 

Common 

N.C. Contact 

1 2 3 4 5 6 7 8 


Door Strike relay does NOT follow LED 

(Alternat I/O setting) 


Remote Unit 

N.C. Contact 

Common 

N.O. Contact 


follows Aux input on 

Central 


C 

Central Unit 

R 


LED signal from panel 

only activates LED on 

Remote 

Auxiliary Digital I/O #1 

Input triggers Strike 

Relay 


Door Strike Contacts

Alarm Relay Alternate I/O Setting: 

In the Alternate I/O configuration, the Alarm relay on the Central is activated when the Auxiliary 

digital input signal is triggered on the Remote unit. The alarm function is re-assigned to Digital 

Output #3. In other words, The Alarm function and Digital Output #3 will swap places ON THE 

CENTRAL SIDE. 

This setting is used when a dry contact output needs to be sent from the Remote to the Central 

unit. 


Alarm and Digital Output #3 Swap functions 

(Alternate I/O setting) 


Functions as Alarm Output 

1 2 3 4 5 6 7 8 

Panel Interface #1 Panel Interface #2 

N.O. Contact 

Common 

N.C. Contact 

Relay Contacts follow Aux 

Input #3 on Remote 

Central Unit 

N.C. Contact 

Common 

N.O. Contact 


C 

Relay Contacts follow Aux 

Input #3 on Remote 


Functions as Alarm Output

Auxiliary Inputs and Outputs: 

There are several additional low power I/O points that can be used on the Duprex-7000 series. These 

I/O points provide electrical signaling from the Central to the Remote and back from the Remote to the 

Central. 

Each output is a 0 - 5 volt digital logic signal level and can sink up to 25 mA. If additional power 

handling 

is required, an external relay or I/O module can be used. 

Each input also uses 0 - 5 volt digital logic signal levels. Each output will follow the status of its 

associated 

input. A signal change on Input #1 will be seen on Output #1, input 2 on output 2, input 3 on output 3. 

A logic low (0 volts) on the Alarm Digital Input will activate the Alarm relay on the Central unit. 

Relay contacts can be used with any voltage up to 120 VAC 

Auxiliary I/O uses 0 to +5 VOLT signals only 

Reader #1 Auxiliary I/O Connections 




Alarm Supervision Relay N.O. 

Alarm Supervision Relay Com 

Alarm Supervision Relay N.C. 

The Alarm supervision relay will close when both 

the Central and Remote units are powered up and 

communicating. 

Both Reader 1 and 2 relays will open if 

communication 

is lost. 





C 

1 2 3 4 5 6 7 8 

R 

1 2 3 4 5 6 7 8 


Auxiliary Inputs and Outputs 

Relay contacts can be used with any voltage to 120 VAC 

Auxiliary I/O uses 0 to +5 VOLT signals only 

C 

R 

Reader #2 Auxiliary I/O Connections 

Alarm Supervision Relay N.C. 

Alarm Supervision Relay Com 

Alarm Supervision Relay N.O. 









Using Auxiliary Inputs and Outputs: Digital Inputs 

Direct connections to the Auxiliary I/O operate at a maximum of +5 Volts. They can be used with 

most standard system control voltages using the techniques discussed below. 

The Digital I/O signals can interface directly to panels and readers that use 5 Volt signal levels. Each 

Digital I/O point is capable of sinking 25 mA of current. Application of voltages greater than 5 Volts 

can damage the board. 

The digital inputs are pulled up to +5 Volts and operate as active low, that is they will operate when 

connected to ground ( 0 Volts ). They can be driven by a digital output from a panel or reader, by an 

open collector output, or by a relay contact connected to ground. 

In no case should a Positive voltage greater than 5 Volts ever be applied to the digital inputs. 

Here are several examples of driving the Duprex-7000 series digital inputs using standard field 

wiring practices. 

Ground 

Activating a digital input with relay or switch contacts. 

Digital Input 

Ground 

Activating a digital input with open collector output device. 

Digital Input 

Open Collector Output 


Using Auxiliary Inputs and Outputs: Digital Outputs 

The Digital Outputs also operate at 0 and +5 Volts. They are capable of sinking 25 mA and 

sourcing 0.5 mA. As digital signals, they can be interfaced directly to electronic equipment 

utilizing 5 Volt logic level signals such as panels and gate controllers. Check the manufacturers 

specifications for the equipment that you will interface to the Duprex to verify signal levels. 

Other external devices such as magnetic or solid state relays can be used if more drive 

capability is required. 

Activating an external relay with a digital output. 

Use a relay with a 5 volt coil and requiring less than 25 

mA 

drive current. 

+ 5 Volts from Duprex 

K 1 

Digital Output 

Relay Contacts 

Activating a Solid State Relay. Use a relay with a 5 

volt input and requiring less than 25 mA drive current 

such as the Opto 22 or Crydom products using a logic 

level input. 

See relay manufacturers documentation for electrical 

and connection requirements. 

+ 5 Volts from Duprex 

K 1 

Digital Output 

Solid State Relay Contacts 


K 1

Supervised contacts and programming resistors: 

One of the features of the Duprex is that it supports the use of supervised contacts. By setting 

programming resistors on the Central unit, the status of contacts and end of line resistors on the 

Remote unit can be monitored. 

Two of the inputs support supervised contacts. The Alarm and Digital I/O #3 can operate in 

supervised mode. 

Supervised mode uses the programming resistors on the Central unit to determine what value of end 

of line resistor it should sense on the Remote unit. If the value of the programming resistor and the 

end of line resistor is equal, the output is not activated. If they are not equal, the output is activated. 

End of line resistors from 1K (1000 ohms) to 20K (20,000 ohms) can be used. The resistor for the 

end of line should match the value of its associated programming resistor. 

C 

R 

Ground 

Digital I/O 

programming 

resistor 

Ground 

Alarm 

programming 

resistor 

Digital I/O #3 Alarm 

Contact and end Contact and end 

of line resistor of line resistor 


Supervised mode for Digital I/O #3 will operate in the same 

manner as the Alarm input shown below, except the Digital 

Output #3 will be activated on Central unit. 

R 

R 

Ground 

Ground 

Digital I/O #3 

Contact and 

end 

of line resistor 

Digital I/O #3 

Contact and 

end 


Alarm 

Contact and 

end 


Alarm contact closure 

changes end of line 

value, Alarm relay 

will be activated on 

Central unit. 

Line broken changes 

end of line resistance 

value. Alarm relay 

will be activated on 

Central unit. 

Alarm 

Contact and 

end 



Application of supervised contacts - End of Line Resistors 

Some Access Control Panels utilize “End of Line Resistors” (EOL) to monitor the status of the wiring 

to the contact point. The Duprex system can be configured to support these types of circuits. 

The Duprex system can be configured to allow the Access Control Panel to monitor the End of Line 

Resistor. Resistors from 1k to 20k can be used. 

Panel Terminals 

Typical Panel with End of Line Resistor circuit 

Contact switch 

with EOL 


Application of supervised contacts - End of Line Resistors 

In this application, 3 resistors are used. The EOL resistor at the Remote contact, 

the programming resistor on the Central unit, and a resistor accross the contacts of 

the relay on the Central unit. All 3 resistors should have the same value 

C 

R 

Ground 

Ground 

Programming 

Resistor 

Alarm Contact 

and end 


To Access 

Control 

Panel 

Should the circuit change resistance on the remote end, the Central relay will activate. The 3rd 

resistor on the Central relay provides a matching resistance for the Access Control Panel.

Cypress Duprex

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