CONNECTING THE TERMINATION RESISTOR AND DIODE

A resistor is inserted for line’s impedance matching to prevent distortion and reduction in RS-422 or RS-485 long distance data communications, which is referred to as termination resistor.

Note that termination resistors of lower than 90 for the communications system.

"

RS-485

RS-485

A

Mon 12 / 12 / 2009

 

 

RS485/RS232

 

 

 

 

10 : 30 : 20

 

 

 

 

 

 

 

 

 

 

 

 

Converter

 

 

 

4

5

6

F4

F5

F6

 

 

 

 

1

2

3

F1

F2

F3

# 120Ω

 

 

B

7

8

9

F7

F8

F9

Termination Resistors

120Ω

ESC 0

ENT

F10

F11

F12

 

 

 

 

 

 

 

 

 

INSTALLATION AND EXTERNAL CONNECTION

BYPASS DIODE CONNECTION

If you connected an inductor (door locks or alarm device) to the output relay, there should occur a surge voltage while the inductor was turning on and off. If you do not connect a bypass diode to the relay, the surge voltage will cause damage to the electric circuit of the controller. To reduce this surge, it is recommended to connect a bypass diode between the devices.

Mon 12 / 12 / 2009

10 : 30 : 20

1 2 3 F1 F2 F3

4 5 6 F4 F5 F6

7 8 9 F7 F8 F9

ESC 0 ENT F10 F11 F12

DC12V

GND(-)

Lock/Alarm

Cathode Anode

1N4004~1N4007 or equiv.

English _ 15

Page 15
Image 15
Samsung SSA-S2100/EXP manual Connecting the Termination Resistor and Diode, Bypass Diode Connection