2 wire RS485


Thread Starter


Hi guys,

I'm using a PC to network with a control techniques motor drive (UD70) via a 2 wire RS485 connection. I encounter this problem where the transmittion "hangs", i.e. the drive side continues to send (doesn't stop!) when it's not supposed to. This happens if i'm sending and receiving a big array of say, 200 elements.

I'm wondering if the sending and receiving is happening too fast for the 2 wire connection to cope which causes the "hanging".

Did anyone here encounter a similar situation or has an explaination to offer?

Thanks for any replies :)
Try these:

-Check if the load resistor in the rs485 network is already set.
-Set the lower baud rate
-If there is still a problem then replace the rs232/rs485 converter in the PC side with the better one:
1. rs232/rs485 converter with dc power supply
2. opto isolated rs232/rs485 converter