Matrix user forums

Can anyone help here, im trying to communicate with a TTi 1705 multi meter via RS232 with the intent of being able to change modes ie OHM's, volts, continuity and Freq etc at a push of a button away from the meter. The meter's Baud rates are 2400, 9600 or 19200.

The data sheet for the meter says Pin 2, 3 and 5 may be used as a conventional RS232 interface with XON/XOFF handshaking. Pins 7,8 and 9 are additionally used when the instrument is connected to the ARC interface. Signal grounds are connected to safety ground.

Do I need handshake it I am just sending commands?

Thanks

Tony

Hello Tony,

I would start by connecting the TTi up to your computer using a USB to RS232 adapter cable and then use a terminal emulator program like RealTerm to try and talk to the device. The RealTerm application should let you switch the XON/XOFF flowcontrol on and off so you can test to see if it is needed and what is the correct protocol before diving into the embedded program.

Here is some info on XON/XOFF - http://en.wikipedia.org/wiki/Software_flow_control