RS232/RS485 PHOTO ISOLATOR CONVERTER

Product Code : A485CONV/E(U)
The RS232 to RS485 photo isolator provides a RS232 signals to RS485 signals conversion features, which are used to expand long haul communication distance via multi-drop communication of RS485 signal, and it allows the input signals to be completely prevent up to 1000V. There are 3 LED indicators correspond to Tx, Rx, and power signals. A 9V, 500mA power adapter is provided in the package.

The features of RS232 to RS485 photo isolator are :
Standard EIA RS232 to RS485 converter interface.
Photo isolator function that prevents signals up to 1000V.
Transmission distance up to 1200m.
Female RS232 connector.
Male RS485 connector.
9V, 500mA power adapter.
Point to point or multi-drop available.
Provide auto flow control.

Check that your RS232 to RS485 photo isolator package includes the following items :
RS232 to RS485 photo isolator.
DB 25 pin cable.
User manual.
Warranty form.

Hardware configuration:
The on board jumpers can be used to set flow control and delay time.

JP1 (Jumper 1) 

Set GND photo isolator.

JP2 (Jumper 2) 

Set +5V photo isolator.

JP3 (Jumper 3) 

Set RTS photo isolator.

JP4 (Jumper 4)

Set  RX photo isolator.

JP5 (Jumper 5)

Set TX photo isolator.

JP6 (Jumper 6)

Select flow control.

JP7 (Jumper 7)

Select delay time when auto flow control is set

VR 

Adjust delay time



1.  Set GND isolator
     JP1
  
The JP1 is used to set GND isolator. When short pin 1 and pin 2 means disable GND isolator (the input & output of DC converter are connected together), otherwise, GND is isolator. This jumper is used for testing only; in general you must open it.
Pin Mode
Open 1,2 GND Isolator
Short 2,3 GND of  Input & Output be Connect Together
This Jumper For Test use only you must Open it                    

2.  Set +5V Power isolator
     JP2
  
The JP2 is used to set +5V power isolator. When short pin 1 and pin 2 means disable power isolator (the input & output side use the same +5V power), otherwise, photo isolator is set (the input & output side use the different +5V power). This jumper is used for testing only; in general you must open it.
Pin Mode
Open 1,2 Input & Output Side use the differ Power Supply
Short 2,3 The Input & Output Side use the sam Power of +5V
This Jumper For Test use only you must Open it                                   

3.  Set RTS photo isolator
     JP3
  
The JP3 is used to set RTS photo isolator. When short pin 1 and pin 2 means disable RTS photo isolator, otherwise, photo isolator is set. This jumper is used for testing only; in general you must open it.
Pin Mode
Open 1,2 RTS Signal be isolate by Photo Isolator
Short 1,2 Direct Connect RTS Signal To Output side
This Jumper For Test use only you must Open it                    

4. Set RX photo isolator
     JP4
  

The JP4 is used to set RX photo isolator. When short pin 1 and pin 2 means disable RX photo isolator, otherwise, photo isolator is set. This jumper is used for testing only; in general you must open it.
Pin Mode
Open 1,2 RX Signal be isolate by Photo Isolator
Short 1,2 RX Signal Go To Input side directly
This Jumper For Test use only you must Open it                    

5. Set TX photo isolator
     JP5
  

The JP5 is used to set TX photo isolator. When short pin 1 and pin 2 means disable TX photo isolator, otherwise, photo isolator is set. This jumper is used for testing only; in general you must open it.
Pin Mode
Open 1,2 TX Signal be isolate by Photo Isolator
Short 1,2 TX Signal Go To Output side directly
This Jumper For Test use only you must Open it                    

6. Select auto flow control
     JP6
  

The JP6 is used to set auto flow control. When short pin 2 and pin 3 means auto flow control, user only need to send data from Tx signal, the hardware will control RTS signal automatically. When short pin 1 and pin 2 means RTS flow control, while user need to send data, it needs to set RTS signal to 1, to enter driver mode, then send message or data. After sending message, it needs to set signal to 0 to enter receive mode again.
Pin Mode
Short 1,2 We use RTS For  Flow Control
Short 1,2 Auto Flow Control

7. Select delay time
     JP4
  

The JP7 is used to set maximum delay time when auto flow control is set. To short pin 3 and pin 4 means maximum delay time is 4.6 ms, and short pin 1 and pin 2 means maximum delay is 40 ms. To adjust maximum delay time, please adjust VR.
Pin Maximum Delay Time
Short 3,4 4.6 ms
Short 1,2 40 ms

4. VR

The VR is used to adjust maximum delay time. Please use the software in the shipping package to adjust it.
RS485 Cabling Information for DB25

The RS485 signal assignment is shown as follows.
Pin Description
2  TRD +
3   TRD –
7
 Ground

The RS485 communication is based on cable sharing method, which is connected as following:
Computer at site 1 Computer at site 2
TRD+ TRD+
TRD - TRD -
Ground Ground


RS232 Cabling Information for DB25
The communication interface follows the EIA RS232 standard.  The signal assignments for a standard DB25 connector are shown below:
DB25
  Pin  #     Signal Name
  RS-232C
Name
 Signal
Direction
  2  Transmit Data(TxD)  BA
 Output
  3  Receive Data(RxD) BB
 Input
  4  Request to Send(RTS) CA
 Output
  5  Clear to Send(CTS) CB
 Input
  7  Signal Ground(SG) AB
 Common
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