7i96s + 7i85 and two daughter cards 7i84 + 7i87

Hello to the Linuxcnc community.I’ve been digging through the forum quite a bit. Finally, this is my first post and I promise it won’t be the last (sorry for that).I started to set up my little system. Which hopefully once will be something in between a 3d printer and a cnc mill. Well, in the end it should print parts, but the whole project is even a preparation for a possible Micron retro fit. That means I will add stuff and do things in a way as it is probably not really necessary for a 3d printer. I started the system with the 7i96s and 7i85. I flashed the 7i96s_7i85d.bin and got the needed 6 stepgen, 4 encoder and a few IO’s , smart serial and so on. I connected the e-stop signal to an input and got axis reacting to its state. I even got the machine state on axis following control power through a small classicladder program.Since that was running well, I added the 7i84. Connected to the smart serial port of 7i96s. Even that worked fine, so I added two pages to axis. One additional tab, where I can switch on and off some outputs. The other page is next to tab window. It shows the current state of those outputs, that’s because I even want to see the state when running in auto. Next step is to connect 7i87. That’s where I have some problems. My idea is to use the first serial port from 7i85 to connect 7i87. The documentation mentioned it is easy to use the serial ports as smart serial interfaces. Well, I can’t get rid of the red led on 7i87.Then I swap cards and connect 7i87 to the smart serial port of 7i96s. Now the greed led is lid on 7i87 and card including pins show up.Is it so that I need another firmware to be able to use a serial port on 7i85 as smart serial port?

Its likely you need to enable the desired sserial channels in the hal file
This is done in the driver config line, with something like:

sserial_port_0=123xxx

Where 1,2,3 are the modes for sserial channels 0,1,2 and x means disabled)
(sserial channel 0 is on the 7I96S, channels 1 through 5 are on the 7I85)

Green, now it is green!
thank you for that explanation.
It even helps me to understand other posts regarding the serial port.
Appreciate it.