Application Example for Smatlab Photo Isolator Inpu

Digital Input

Many types of digital signals like switch closures, relay contacts, and TTL laver compatible can be read by digital I/O card directly. Some type of digital signals input may require signal conditioning like reduce higher-level voltage to TTL level. A variety of signal conditioning module is available to provide isolation and device circuitry protection functions.


Switches are pretty straightforward to wire. For security reason switch contacts are always drawn in the OFF position when in systems initialize. In the case of rotary switches the wiper arm will always be connected to the first contact, which will be the off position.

Data Sheet -
download file: 4N35.pdf

* Signal Input with Power
* Signal Input without Power

SENSOR To 8 Photo Isolator Board
Application Example
Proximity switch
[ General Specifications ]

Operating Voltage

10 - 30 V DC


Less than 10 %

Max. Switch Rate

1.5 KHz ( M12/M18 ) ; 2K Hz ( S17/S18 ) ; 500 Hz ( PB )

Power-On Reset Time

20 ms

Circuit Protection

(a) output short circuit & (b) reverse polarity of supply voltage

Max. Load cirrent

100 mA


Conforming to IP67

Cable Length

2 meter, oil retardent, grey color

Writing Diagram

Brown, black and blue as standard

Proximity switch

1. 8 Photo Isolator / 8 Relay Board Jumpers Setting
 a. JP XA  JP XA ( Short 2,3 )
 b. JP XB  JP XB ( Short 1,2 )

JP0B to JP7B are used to select isolated or non-isolated. When JPXB-1, JPXB-2 is short, then the corresponds channel is in isolator mode, When JPXB-2, JPXB-3 is short, the 1XL is short with system Gnd. So the external signal is in non-isolated mode. JP0A to JP7A are used to select power signal input or non-power signal input for the correspond channel. JPXA-1 and JPXA-2 short is power signal input mode. JPXA-2, JPXA-3 short is non-power input mode.

 c. JP17 ( Short  1  3 )
JP17 is used to select internal or external power supply of input channels. When JP17-1 is shorted, the PC bus +12V power is selected. When JP17-2 is shorted, the PC bus +5V power is selected. If we short JP17-3, then the external power supplier is selected.

 d. JP18 ( Short 1,2 )

JP18 is to select external or PC bus power supply. JP18-1, JP18-2 short mean PC bus power, JP18-2, JP18-3 short mean external power. Suppose you connect more than two 8 channel relay output / isolator input boards, we suggest you use external power.

2. Sensors Line
a. Brown  Connect to +12V ( Vcc ) & I10H ( 8 Photo Isolator / 8 Relay Board)
b. Black  Connect to I10L (8 Photo Isolator / 8 Relay Board
c. Blue   Connect to Ground ( Gnd )

3. Circuit

4. If the sensor is near the iron, the sensor is on. And the LED11 will be light of 8 Photo Isolator / 8 Relay Board.

5. Signal Input without Power


Device Driver
Self Test Software & Sample Code

Web Based DAQ


Q & A