IKD1M 8440-2028 and 8440-2116 can be used for easYgen-3000XT external digital I/O extension.
8440-2028 was originally made for legacy GCP-3x Line. So CAN ID has to be changed with
this Software tool
https://wss.woodward.com/manuals/PGC/SW_Tools/IKD_Config_Tool/9927-2094_A.zip
8440-2116 IKD1M is based on same hardware like 8440-2028.
If you use 8440-2116 IKD1M you can connect at least the first IKD1M without configuring it.
8440-2116 CAN ID is pre configured to auto connected to easYgen-2000/3000/XT and DTSC-200 .
The 2nd, 3rd and fourth IKD1M CAN ISD must be configured with above shown software tool