Here’s what I know about 7100…
You can use a RIB with a 25 pin TTL straight to a UDC, no translator after the RIB, or you can use the newer programming cable and go “direct” res-232 to UDC via miniaturized and integrated translator.
I’ve used both. They are both transparent to RPM. When I got the 7100s, they came with a rib and a version of firmware that required me to hold buttons when powering up. Then, I finally got them working with firmware and DSP that supports AES256 iCall on P25C and suddenly, attaching a programming cable to the radio causes it to enter programming mode automatically.
Upgrading the DSP also made a zeroize much more straightforward… before, there was a sequence to zeroize, but it was also an unspoken rule (or maybe in a TSM) that after a zeroize, you had to wait for 30 seconds before using the radio or keyloading because the radio wasn’t actually done zeroizing, but you would have no way of knowing!! The new DSP now has a “wait” screen that forces you to wait until it’s actually finished.
It took serious troubleshooting and digging over a two month period to fix AES256 and P25C unmuting but it was worth it! The radios are perfect for my small rental outfit when privacy is a concern and you think the client has butterfingers…
-B