converting a tos/intos fngj 40

got my mesa cards today, a 7c81 and a 7i77. If i read this correctly i need to flash the firmware to the 7c81, in my case i would guess the 7c81_7i77x2d.bit, but i cant find anything in the 7c81 manual. do i have have to flash the 7i77 too or does it come preloaded with firmware?
and another question about the wiring: the 7c81 has a 5v in, so no worries. the 7i77 has a field power and a 5V. Whats here the preferred way: supplying 5v to the 7c81 and configuring the 7i77 so that it gets the 5v from the 7c81 and connect the "field power to the 24V of the machine? or is it possible to connect only the field power to 24v and power the all cards and the pi from there?

1. The 7I77 does not need to be flashed

2. Typically it's better to power the 7I77 by an independent 5v connection to TB1

The 7I77 5V draws about 400 mA by itself and encoder power adds to that
so it's often  a bit much to ask from the 4x 28 Awg wires in the flat cable.

3. There is no connection of field power to 5V power, you need to supply both

The servodrive was orginally connected to j2 pin1 and pin2, but since the the 7i77 has only single ended output for the drive I need to connect it to j1 pin2. Is that correct?

   

It look like J2 pins 1,2 are the differential analog input

So I would wire:

 7I77AOUT --> J2 pin 2   (non inverting differential input)
 7I77AGND --> J2 pin 1  (inverting differential input)

So you think the j1 pin 2 serves a different purpose?

So you think the j1 pin 2 serves a different purpose?

I don't know, but since the original system used J2 pins 1,2
I would use them.

another question regarding the 7i77:
i have hooked up the field power to the secondary output of my power supply, but the voltage breaks down. So i have hooked it up to a separate 12V Power supply delivering max. 1A, but same behavior, the voltage breaks down even if I separate vin and field power
I have checked field power and Gnd, they are not shorted, like in another thread mentioned.
The manual says "Field power must have a ramp up rate of less than 10V/Millisecond", I am no expert, but plugging a switching supply in the mains should not not exceed that!?

Thaks, I was about to answer that I checked it 3 times, but i went in workshop and checked it a fourth time, and guess what, someone has has plugged the cables in the multimeter reversed...

I have flashed the 2x7i77 file to my 7c81 and made a config based vaguely on this tecnique:
i made the config using 5i25 and the single 7i77 template.
when i try to start linuxcnc fails and says that it cant find the first pin (like there was no field power).
Could there be a problem with my config?
7i77 is connected to p1, pncconf shows the the 7i77 tabs at SS#0 and SS#1 and p2 p3 are free to configure. do i have to edit the hal manually (except the rpspi and the name of the card of course, I have already done that)?