The loopback mode (store and forward) repeater will work with all versions of firmware on all Digi radio modems. It is important to keep in mind, though, that the Data In (DI) buffer size on our modules has changed with firmware versions. This can affect the amount of data a repeater is able to store and forward.
Following are the approximate buffer sizes:
For the Loop Back adapter to work properly with RS-232, only pins 2 (RXD) and 3 (TXD) need to be shorted together. You may use a bent paper clip in place of the Loop Back adapter.
Aug 23, 2017