Can i use the fastbal II program on CSI 2120 by directly connecting to the buffered output terminals keyphasor/ Radial to the bently nevada online system. pl advice on sensor settings DC offset etc.Any extra attachment required or just a bnc cable

I'm assuming you are using the 444C adaptor for 2 BNC's in? A +/- 5 TTL signal should work from the keyphasor and if you are reading the eddy current probe you will want to kill the sens pwr in the 2120 and for balancing your sens setting is relative so repeatability is more important than amplitude accuracy - volts/fort nights are OK.

Hopefully someone else will weight in on this one that is better on the 2120.

The 2120 Tach will fire off of a prox probe Keyphasor with the 444C adapter and usually without it, too. Be aware, for balancing purposes there is an electronic phase lag using the adapter of approx 40 degrees, but its best to confirm this with a photo tach input to the meter from the machine you are balancing. That is if you can stop the machine to add reflective tape! However, if you are going to use the balance program and go through the trial weight process with several start and stops, you won't need to worry about the phase lag other than noting it when using the adapter (when the machine is off, add the tape anyway, it will help when you use the rules of balancing rigid or flexible rotors in understanding system lag angles). You will need a Volt adapter to take in the prox probe signal to the 2110 using a BNC cable with the meter sensor power off and you will need to know the prox probe sensitivity (usually 200mV/mil). No DC offset, leave in AC Coupled mode. Are you balancing a turbine/generator or some other machine? Flexible rotor or rigid? Speed?

Good points; you can make a box BNC in 100 mF and BNC out to cleanup a signal for tach purposes.

I generally just collect the data and make the calculations outside the box .... If you do the balance; save all data and one-shot it next time.

It looks like you'll be balancing using the online system prox-probes. Keep in mind that the 1X vectors shall be slow roll compensated (especially if the runout is substantial).