CBX-500 question, FRF.8

I am working on a solution that will require my CBX-500 to do
transparent mode and not translation mode. I've grepped the docs I have
and looked on the web and can't find reference to which mode the CBX
uses. This cross connect would be between the FR 3/1 card to the ATM DS3
card. Does anyone know which mode the CBX uses ?