OpenICE can't get data from MX800

I have OpenICE working correctly with a Philips MP70, but I need it to work with the MX800.

Following the exact same process for connection with the MX800, I wind up with the unplugged "no data" indicator on my MX800 in the OpenICE devices list.

One thing that stands out to me is the difference between the MIB/RS232 port on the backs of the monitors. The MP70 has two separate ports, I assume one for input and the other for output. The OpenICE documentation suggests using the port with the arrow pointing out of the circle, like this: 

O->

The MIB/RS232 port on the back of my MX800 only has one port, and it has a double arrow indicator, like this:

O<->

So I am wondering if this port is configurable as either input or output, and if that is possibly my problem. Does anyone here have any input on this issue?

Thanks.