mesa hardware for mill retrofit

Hello.
What mesa hardware can use for retrofit a mill(heindehain tnc355 controller/ year 1992)
that has 2 bosch servo drives SM 17/35-TA and 1 bosch servo drive SM 10/20-TA.
Thank you.

Hello.
Servo drives have -10v +10v differential analog input without feedback by encoder(servomotors have only tacho not encoder).
The controller is heidenhain tnc 355 and the
linear encoders feedback goes directly to controller.
X1/X2/X3 shown in photo are encoder signals.What are these signals ? 1Vpp ?
Linear scales are heidenhain LS 703C
How can read these encoders with linuxcnc?
Also how can config this type of pid
with speed +-10v analog speed control to drives and encoder position feedback to linuxcnc?
Reading tacho can help somewhere?

If the  machine does not have separate boxes to convert the
1V PP sine/cosine to quadrature, you would need to obtain these. 
These are called interpolators or "EXE" boxes and often available
on Ebay for reasonable prices (search for "Heidenhain exe")
 

I have mesa 7i80hd / 7i33ta / 7i37ta.
linear scales are 1μApp type LS 703C
product.heidenhain.de/JPBC/image/HWP.EN/...029-93_ls_703(c).pdf

I have no exe boxes but i have the original le 355 b controller.
Is possible to steal quadrature signals from inside of controller?
I have seen a thread here that someone with similar controller tnc 155 stolen quadrature
signals from inside controller as described here
www.machineability.com/Bridgeport_series_II.html

I have attached mine controller photos..
where is possible to find these signals?

I have got 3x heidenhain EXE 702 B with 25x interpolation.

For pid tuning analog -10+10V speed mode servo and feedback directly to linuxcnc
from heidenhain exe what needs FF1 & P ?

Did you see this topic?

forum.linuxcnc.org/30-cnc-machines/49758...a-maho-mh600t#281733

The mill has 2 different spindles iso40 taper that share the same inverter.
Selection is done by relay at the output of the inverter.
1 spindle mounted on z axis and 2 spindle mounted on y axis like the mill shown in the video
youtube.com/watch?v=9Qa6oTOpj_I

How can model these 2 spindles in linuxcnc?

vre wrote:

How can model these 2 spindles in linuxcnc?
 

LCNC supports multiple spindles, but you may not need to set up LCNC like that as I suspect your machine isn't intended to run both spindles at once.

Does your machine have some sort of electrical interlock to switch between the two spindles now?  Is there a limit switch or other sensor to determine to which spindle the output relay should be connected?  If not, what determines the relay position now?