Maybe am I a bit formalistic about what real time resolution is and do not accept this EventTiming instrument as something having a real resolution in the nS range, but as a comparison:
It is a bit like a typical network analyzer with upper frequency limit 3GHz, which can measure cable-length with fS resolution. If real time resolution is in nS range, how can it handle signals in fS range? It can't! It is just calculated and interpolated numbers from available measured data (with bandwidth below 3 GHz).
Real time signal resolution can not be better then the actual bandwidth, which is relative moderate in this Event Timing instrument. In my opinion is this Event Timing instrument not able to handle anything in pS range, it is calculated numbers based on relative low bandwidth measurements.
If I understand datasheet correct is useable input signal bandwidth less then 100 kHz in single shot mode and for a repetitive signal 50 Hz. It is probably a limitation to allow for some processing between each pulse. There are also other things that limits how fast signals it can handle at signal input.
As RF engineer did I react on the analog delay, about 5 meter, close winded as it was single shield (lossy) coax, but even worse, was it connected to low-cost BNC connectors:
(
Wednesday0915.pdf). Not serious RF, but as it actually not need to handle any RF is it probably good enough.
These BNC inputs are used for trig of internal calculations and as long as it is relative long risetime of trig-signal do it probably work ok, but trying to feed these inputs with complex pulses or signals with XX GHz bandwidth would give very unpredictable result. Even at 1 GHz do I not recommend BNC in a professional design and these do I assume have a self-resonance below 10 GHz.
Principe for what they call EET (Enhanced Event Timing), is relative understandable in **broken link removed**
Reminds me a bit about how the 15-pin d-sub for joystick was designed that was common on PC 10 years ago. The joystick did contain variable resistors. A software trig started a internal clock and also started charging a cap via joystick resistor until a certain voltage stopped the clock. Number of clock ticks did correspond to resistor value.
In this case are same main components used as for the joystick but in a bit different configuration. It is the incoming signal that is the trig that polls a clock via a integrator.
Via A/D is remain done in software. A bit simplified
. Existing models do not seem to have implemented the 100 MHz RTC with GPS sync but it is described in some papers as a possibility to add a real time stamp.