Problem Reading data from BH485-DO Sensors using RS232-485 converter

[spinix]

HI i am trying to read data from a RS485-DO sensor using RS232-485 conveter and a modbus(mtester) .
am getting error no POD detected.
when i use simply modbus master timeout error

any suggestions on how to proceed .

thanks in Advance

 

[KlausST]

Hi,

Show your circuit.
Show your code.
And show scope pictures of the communication.

Klaus

 

[spinix]

Hi,

Show your circuit.
Show your code.
And show scope pictures of the communication.

Klaus

hi this is how am connecting .
Appreciate all the help . thanks in advance

 

[schmitt trigger]

There is a very common mistake with RS485: forgetting the termination resistor.
Have you included it?

 

[spinix]

There is a very common mistake with RS485: forgetting the termination resistor.
Have you included it?

First thanks a lot for responding and trying to help.
i Connected this setup with sensors(DO,pH,Temperature) from France with 12v(specified in the specs provided) and able to read them with MODBUS.But the sensors from china BH485 (DO,pH) are not giving any data in MODBUS .No Technical support from the seller .so am struck

Thanks