Hi
i agree the book says they are all the same. Oddly though, i have 3 that are wired different. I have a old s4 that the pinout is way different. I bought a used pendant for a s4c+ and it worked on other models except the estop was wired different in this one. I just took them for the screens and buttons though. They had all similar internals. 2 had different circuit board revisions