RS232 Sensor read with Arduino (wiring and voltage level issue)

Hi,

i have a sensor that requires vcc in the range of 7 - 18 v. The sensor output is RS232 RX/TX.
Obviously, the sensor needs a seperate power supply and can not be operated with the arduino 5v output.

I would like to read the sensor values with the serial port of my arduino uno.

Can I use the RX/TX output and connect it directly with the arduino, or should I use a TTL adapter inbetween?
Is it necessary to connect the ground of the sensor power supply with the arduino power supply?

Thank you for any hint or tip,
Hans

HaPeWe:
Hi,

i have a sensor that requires vcc in the range of 7 - 18 v. The sensor output is RS232 RX/TX.
Obviously, the sensor needs a seperate power supply and can not be operated with the arduino 5v output.

I would like to read the sensor values with the serial port of my arduino uno.

Can I use the RX/TX output and connect it directly with the arduino, or should I use a TTL adapter inbetween?
Is it necessary to connect the ground of the sensor power supply with the arduino power supply?

Thank you for any hint or tip,
Hans

You must use a TTL/RS-232 adapter. The RS-232 adapter only works if the grounds are all connected. So, you are on the right track for both questions.

Paul