Janus Liquid Handler-Failure to Initialize

Right back here again. yay
This is an issue that just started occurring, being a failure to initialize.
Visually, the varispan arm (the 8 tip adapters, not the entire arm) moves on the y-axis toward the top of the grid until it runs and hits the end. The motor tries to push against what I am assuming is the end of the track or a wall, pushing a few times, realizing it cannot move furthermore, and these errors pop up.

“Error 769: WinPREP Error
The Varispan pipetting instrument failed to initialize.
The Varispan pipetting instrument failed to initialize.
Extended error information:
Y motor fault while homing Z1”

and

“Error 512: EGS Module Error
The instrument is not initialized”

When you try other functions, such as a protocol, a preprogrammed diagnostic test, parking arms, or calibration, it will first automatically initialize. But it fails initializing and thus there is nothing you can do with the robot until it initializes. This has happened a few times. Before, if you keep repeating to initialize (maybe 10-20 times), it will by some miracle fix itself and we can move on with our lives. This last time however, I spent an hour initializing over and over with no change and now our robot is temporarily out of commission.

There are some theories around the lab. One is the Janus does not remember where its arms are when it turns on, maybe being off by a little bit. And so it runs into the top of the grid. We have tried both parking the arms or moving the arms above a specific spot before turning off but that seems to not have an effect. Another theory is there is an issue with a sensor. Maybe the arm moves north on the grid until a sensor detects it at the top and tells it to stop. A last theory is miscommunication between the WinPREP and the Janus, considering the error is called WinPREP error.

Let me know what you guys think is happening or if others are having the same issue. I appreciate you all.

Hi Kiki,

I’m assuming you’ve done a hard reboot of both the instrument via the power switch on the back of the device as well as a reboot of the controlling computer?

Also, when you say you are moving the arms, are you physically doing this, or with the Winprep control software somehow? Also, are you turning off the instrument before this, or after?

The fact that it’s a Y motor error suggests that either the span of the tips is too wide or there is a location issue with the Varispan head itself. The probes can only move on the Y axis (front to back) in relation to each other, so if they cannot be pushed together enough, or their motors are kind of stuck, they collectively might be reaching the Y maximum range prematurely during initialization. You might need to move the Y motor manually into a position where it can home correctly. If you’re doing this while the instrument is on and the motors are initialized, it probably has conflated values of where it expects to be and where it actually is, as you alluded to in your post.

I would suggest that if you haven’t done so already, shut down both the computer and the instrument (via the back power switch) before doing any type of physical movement of the instrument. The motors will disengage and the probes will probably do a little fall down to the deck. Once that happens, manually move all of the probes and the arm as a whole to the dead center of the deck and spread the probes apart a little bit so they will have to reset upon initialization. You should not feel any real resistance during this step as all the motors should be disabled. Wait 5 minutes before returning power to the instrument and the computer, and initialize again. If you do get successful initialization, it would probably be best do some deck teaching so you can ensure your Janus is not overextending itself outside its expected range.

I’m not exactly sure what do if that doesn’t work and its probably best if you call an FSE or Revvity to come out and fix it.

Good luck!

Doug

2 Likes

Hi Doug!
Thanks for the very prompt response.
I wanted to get back so that you and everyone else knows. I tried this out and did not find success. There must be something additional happening that I am not seeing. Will probably be contacting a technician.
Pray for me while I tell The Boss about this one.
Have a good night!

Oh sorry to hear that. Please let us know if you find the root issue and what the fix is!

Doug

1 Like