PortServer TS4 and RS-485

I am trying to use the PortServer TS4 with the Kohler MonitorIII software to monitor our backup generator. It works fine with a regular serial port or a generic USB to RS232 converter, but I can’t seem to make it work with the Realport profile on the PortServer. According to the mfg’s equipment, it is a RS-485 interface with two wires + ground. Should this work?

I do see some data in the port monitor, not sure what it SHOULD look like.

This setup should work with the MEI version of the PortServer. The first thing I would look at are the DIP switches of the device. Are those setup for RS485 Half-Duplex? The next question I would have is what pins are you connecting to on the Digi device? What version of RealPort are you using? Firmware version on the PortServer?

With these questions answered I would have a better idea as to why you’re not able to communicate to the device.

There are no dip switches unelss they are under the cover. It is a PortSever TS 4 (1P)50000836-15J. I am using the Digi cable RJ45/DB9 Male Straight (76000239) I upgraded to the U2 firmware first thing. The RealPort is 4.2.360.0

The version of PortServer you have does not support RS485 communication, only RS232. You have the standard PortServer TS 4 product. You would need the PortServer TS 4 MEI to allow RS485 communication. This is why you do not see the DIP switches on the device.

How does it work with standard PC RS-232 ports and generic USB to serial converters?

Can I use the same Digi cable RJ45/DB9 Male Straight (76000239) with the PortServer TS 4 MEI?

If the device is working with a standard serial port on a PC, I would have to say that that device is not RS485, or at least not running in a RS485 mode.

I would suggest calling Digi Support for further assistance on this issue, as there are lots of unanswered questions we need to ask.

I just discovered that it has a RS485 to RS232 converter in line. It is line powered and requires 7 volts (pos or negative) on 1, 4, 6, 7 or 8

The unit that you have will not be able to provide power on the serial port. I can only think of 2 ways that you could get a Digi device to work in this scenario, both of which would require a different version of the PortServer TS:

  1. Use the PortServer TS 4 MEI, which can do RS485 natively, and plug directly into the system, bypassing the 232/485 converter.

  2. Use the PortServer TS 4 P MEI, which can inject up to 9 volts of power on the serial port, and hook it into your 232/485 converter. This device would also be able to do RS485 natively, so it would make more sense to hook the connection directly to the Digi.

Yes, the same cable can be used on the PortServer TS 4 MEI, but I’m not sure at this point if you would need this device. Since you are telling us that the device can communicate with a standard PC COM port which is RS232, then it should be able to communicate to our standard PortServer TS 4, which is also RS232. This could be something as simple as a cabling issue, but like I suggested before, it would be best to call Digi Support to discuss the issue in more detail.