EdgePort/1i RS-485 Half-Duplex problem

I have followed the instructions for half-duplex RS-485 communication on the Edgeport/1i device, however I am unable to communicate.

R+ (pin 4) and T+ (pin 7) are tied together.
R- (pin 8) and T- (pin 3) are also tied togther.

Pins 1 and 5 are shorted together per instructions.
Tests ok on digital loopback test.
Operation of RS-485 device has been confirmed with two other USB-RS485 adapters.

When I attempt to make a connection with my RS-485 device, the Windows XP operating system repeatedly makes its connect/disconnect sound as when a new device is found.

Wanted to use Digi product for its robust driver, however there appears to be a serious problem with this device

Please advise.



Will the Edgeport/1i work in a two-wire (Half Duplex) application?


For cabling information, review the Edgeport Industrial model Installation Guide, which contains cabling information for the Edgeport/1i:

Follow the cabling diagram in the Edgeport/2i section (immediately below the Edgeport/1i section) titled “Cable Connections (DB9 Female) for Half Duplex”. Also, as stated in the Edgeport/1i section, for Half Duplex, short pin 1 to pin 5 (GND).

What exactly suggests that you aren’t able to communicate? For example, does whatever software you’re using generate any error messages? Or do you just not see data that should be there?

Are you referring to the sound that Windows makes when you plug/unplug a USB device? If you aren’t sure, unplug the USB cable from the Edgeport and plug it back in and let me know if that’s the sound.