D720S, RS485 comms

[gnusmas 0]

Hello everyone. I am trying to communicate with a Mitisibishi 720S inverter using my laptop. Now I have the following setup. Using a cable with 2 RJ45 connectors on it. I bridged the following connections in the cable, since I want to use 2 wire RS485 connection. Bridged RDA with SDA, and I bridged SDB and RDB. I have a delta IFD6500 which is a RS485 usb to serial converter, it has a RJ45 connection on it. I configured the D720s according to the parameters found on Page 348, and afterwards I power cycled the inverter. Using FR configurator SW3 and setting up according to the parameters inside the inverter. When I click on "online" the display in FR configurator goes to Err immediatly and when it finally times out i get the following error code. "Communication Error Code: 0x80010101" Now i have checked the connections with a multimeter and I get no problems. And I followed the instructions in the FR Configurator and it still does not work. Any help please

[kaare_t 155]

Did you try to interchange the SDA/SDB cables going to the converter?

[gnusmas 0]

Can you eloborate more on interchange?

[Edwin 0]

I believe the wiring will same as attached photo.

[gnusmas 0]

That seems like 4 wire RS485, I initially used 2 wire RS485, I will later today try the 4 wire configuration.

[M1923 0]

There is no 4 wire RS485, it is RS422 which has 4 wires, full duplex configuration. 2XRS485 = RS422 By the way, is there anyone knowing the electrical property of network cable? Is it similar to RS485? The network cable has several pairs twisted wires whose speed is up to 100M, but RS485's can only reach to several M, I don't know why, anyone can help?