Hello, I’m having a very intermittent issue. VMI hydro controller with courion doors, only a 2 stop, every 50-75 runs (or about 3-5 days since it doesn’t run often) car faults out with “CONT FAIL, Delta didn’t pick”. Putting the car on inspection then back into auto clears this and allows you to run for another few days until it happens again. This fault reads the controller didn’t see or lost RON input when R output was activated. I replaced both RON relays (2 soft starts for 2 motors here,this is a 10k # freight) and the R relay. Any advice would be greatly appreciated... Thanks in advance.

Did you replace the delta auxiliaries?

And as working class suggests, are there auxiliaries on the Start contactor?
Broken wires on any terminal or relay connection?

It's a Siemens soft start. No faults on it. Just on the VMI controller.

Oh....guess I didn’t catch that “soft starter” part...oops.
At any rate, it sounds as if the VMI is looking at the Seimans “run/stop” output status and not seeing it “ready” to go. Possible Seimans Logic Card troubles on one of the two starters.
You’ve no doubt tugged and checked all wiring at each starter terminal block and at the VMI controller.
Are you scrolling back in the Fault log to see the sequence of operation prior to the CONT FAIL?
Or- Can you look at what might be the “ready” input on the VMI keypad screen while the unit is faulted to see if it’s present or not?