I am integrating a speed sensor (Honeywell SNDH-T4L-G01) which comprises 4 lines: VDD, VSS, A, B. The last two signals provide speed and direction information in a quadrature format.
These are open collector drivers, therefore in the control unit side a pull-up resistor shall be provided.
As the cable length to the sensor is around 3-4m, I am concerned about the capacitive coupling phenomena, as the quadrature signals are expected to switch at 7khz worst case in a quadrature fashion. I expect that both signals should cross-talk each other due to the weak pull-ups.
Cable shielding is mandatory, however the classical shielding schema (aluminium braid shielded cable with GND connection in one end) would not solve the crosstalking issue in my opinion, due to the capacitance of the line, the weak pull-up of the lines and the strong pull-down driver of the sensors.
Is it a good solution that I shield separately (VDD+A) and (GND+B) with the GND connection (and thus the connection between these shields, to avoid loops) being made at the control unit end?
I know trial and fine tuning is usual in these issues, but I want to start with the best shot possible.