How to split signal between two connectport16 servers

We would like to split incoming data to two connectport16 servers. However, when we do we loose the signal? Is there a recommended spliter? we would like to use the following https://www.blackbox.com/en-us/store/Detail.aspx/RS-232-Modem-Splitter-with-RJ-45-Rackmount-Card---4-Port/TL421-C

However, we cannot seem to get it to work with two connectport16 servers.

I think that is very risky business splitting an RS-232 signal. What is the requirement for this? What product are you connecting to?

Does your end device work when connected via this splitter and only one ConnectPort?

The splitter is not a straight through device as you can see from the pin outs: Pins 3,4,5,7, and 8 connected straight through between the MASTER and PORT 1-n. Pins 1, 2, and 6 “diode ORed” from PORT 1-n to the MASTER port

I would be mapping out the pins to see what is going on.

We are wanting to have redundant pairs of these devices so that if one would fail the other will take over. Our FEPs only talk one at a time so there will be no collisions.

Yes when we connect only one connectport device it works but when we connect the other communication fails.