Internet PLC Forum

General => Technical support => Topic started by: pstiles on November 06, 2006, 06:57:08 PM

Title: RS485 2 wire to RS485 4 Wire
Post by: pstiles on November 06, 2006, 06:57:08 PM

Can you please tell me how I can connect my 4 wire touch panel with the following connections to the two inputs on your T100MD888 plc?

TXD+
TXD-

RXD+
RXD-

Title: Re:RS485 2 wire to RS485 4 Wire
Post by: support on November 07, 2006, 11:38:13 AM

Unless your touch panel manual mentions that the HMI can drive the RS485 in two wire mode you can't use 4-wire RS485 with 2-wire type on the PLC. If your HMI has option to drive the RS485 at 2-wire mode then the HMI should also mention how it is supposed to be connected.  Please refer to the HMI manual on this matter.