I would like to provide some clarity as using the wrong cables can really upset users in the room.
First the break down:
PDN has two system types of operation - PDN or HRI these will determine the cable kits you need to use.
PDN then has two modes of operation - DIRECT or ACCESS POINT these will further determine the cables in the kits that need to be used.
PDN - Personal Digital Node -allows connections only to other digital nodes or rooms
HRI - Hardware Radio Interface - allows connections to mixed mode rooms (Digital & FM)
Cable break down:
You have kits and then you have cables within the kits and soon different cables/kits if you are suing W10 or earlier vs. using W11 or earlier.
W10 and earlier kits/cables:
SCU-39 kit - for handhelds and includes the SCU-19 cable. The SCU-19 is what goes between the handheld (FT-2D, FT-3D, & FT5D) for PDN and HRI modes. The other cables in the kit are for HRI operation purposes. With those HRI cables you will either use the one audio cable for DIRECT operation or both for ACCESS POINT operation.
SCU-40 kit - for mobiles and includes the SCU-20 cable. The SCU-20 is what goes between the mobile (FTM-100D, FTM-200D, FTM-300D, and FTM-400 series) for PDN and HRI modes. The other cables in the kit are for HRI operation purposes. With those HRI cables you will either use the one audio cable for DIRECT operation or both for ACCESS POINT operation.
W11 and earlier kits/cables:
SCU-57 kit - REPLACES THE SCU-39 KIT - Does the same functions as listed under the SCU-39 but is compatible with W11
SCU-58 kit - REPLACES THE SCU-40 KIT - Does the same functions as listed under the SCU-40 but is compatible with W11
SCU-55 cable - replacement for the SCU-19 cable and is included in the SCU-57 kit (cable cannot be sold separately)
SCU-56 cable - replacement for the SCU-20 cable and is included in the SCU-58 kit (cable cannot be sold separately)
I stressed using the right cables because if you are in HRI mode and into a mixed mode room and ONLY using the SCU-19, SCU-20, SCU-55, or SCU-56 cable that is rude operation. Why? Because analog users will have their radio key-up and will only have a dead carrier and no audio. That kind of operation helps to insert wedges when you have users who do not want digital.