Wireless: Why do I hear an echo in Tempest BPs when I connect the base station to a Riedel Matrix 4-wire port?

Question:  I have connected my Tempest 900 system to a Riedel Artist matrix system using the 4-wire connectors on the Tempest base station.  My wireless beltpack users now hear an echo in their headsets, I've checked the mic gain settings on the beltpacks, the echo cancellation circuit on the Tempest base station is activated and there no talks open to Tempest at the Riedel user panels.  When I unplug the 4-wire connections from the Riedel frame the echo is gone.  What should I check for on the Riedel ports connecting to Tempest?
Answer:  Check the software setting for the ports on the Riedel frame that connect to the Tempest base station.  The 4-wire port should be set to "4-wire normal".  If the port setting is set to "4-wire split" it is possible that some echo / delay will be introduced back into the Tempest 4-wire ports.