Troubleshooting

Introduction

During your time scanning at the XRF Core Scanner Facility there are a variety of problems that could arise relating to the software and/or hardware components of the Avaatech XRF core scanners. This troubleshooting guide provides assistance for the users in the detection and the correction of potential and common problems. However, if you are not comfortable preforming one of the following tasks, or if you have any questions related to the following procedures, please contact the Lab Manager for additional assistance.

How to Recognize an Error Message

While scanning core sections on the Avaatech XRF Core Scanner you may notice that you are unable to start a run, or the machine has stopped in the middle of a run this is one way to indicate there is a problem with the instrument and/or software. An error message symbol will appear on the instrument's control panel if there is a problem. The error message symbol is a triangle with an exclamation point that appears in the upper, right corner of the scanner control screen (Figure 1).

The figure shows the main control panels for the old XRF instrument and new XRF instrument. An error message symbol, triangle with an exclamation point, will appear in the upper right corner of the screen. Click on the error message symbol to read the error message.

Figure 1: The old instrument's and the new instrument's control panel main menu. If there is a problem with the instrument or software component, an error message will appear on the scanner control screen. Click on the error message symbol to review the error message.

The first step to diagnosing the problem is to view the error message on the control panel.

To view an error message on the old instrument follow these steps:

1. On the touch panel you will see the error message symbol (Figure 1). Press on the error message symbol to open the PLC Status Log window, and view the error message.

2. The PLC status log window will appear providing you with a brief description of the error message (Figure 2).

3. To clear the errors off of the machine, you will need to click on the check mark in the bottom corner. When you press on the check mark the machine acknowledges the error message (Figure 2).

The figure shows the old instrument's PLC status log window, which is used to view any error messages on the machine. Also, to acknowledge the error you will need to click on the check mark in the bottom corner of the screen.

Figure 2: The PLC status log window allows you to view the error message on the old instrument. You will see a brief description of the error. To acknowledge the error message click on the check mark in the bottom corner before clearing the error message.

Complete the following steps to view an error message on the new instrument:

1. Open the scanner control software.

To open the error log toggle over the options menu. The options menu is in the left, upper corner of the software screen (Figure 3).

2. Scroll down to the bottom of the options menu. Click on “log error” and/or the “active error” option to view the error message (Figure 3).

3. Clicking on the “active error” button will display the most recent error message (Figure 3).

The new instrument's scanner control software. To view error message click on the "active error" button that can be found in the menu options available.

Figure 3: To view the error message open the scanner control software. Click on the "active error" button to view the current error message. Like the old instrument, you will see a brief description of the error appear on the screen. In the menu options, you will also see a "log error" button. If you click on the "log error" button allows you to view the time the error occurred a very brief description of the error message.

Following the troubleshooting guide, you will be able to diagnose and fix the a number of the possible software and/or hardware problems associated with the Avaatech XRF Core Scanners. This troubleshooting guide focuses on common errors easily fixed by the user. However, there are times where new problems occur and you will need additional assistance. If you continue to have problems or have any questions please do not hesitate to contact the Lab Manager and/or Technician. We are here to help and assist you while you are visiting the laboratory!

Complete a Hard Reset or Recover from an Emergency Shutdown

In the troubleshooting guide you will notice a number of the problems with the XRF involve you restarting or shutting down the instrument. Follow these instructions to help you complete a hard reset of the instrument and/or the computer (steps 1-12). If you are scanning a core section and hit the emergency stop button follow steps 7-12 in this guide to recover from pressing the emergency stop button. By following these steps you will be able to quickly restore functionality to the instruments.

To complete a hard reset:

1. Turn off the helium supply to the XRF. To turn the helium off on the old instrument you will press the helium button on the front panel of the instrument. To turn off the helium on the new instrument you will open the scanner control software and click on the "helium" button. Make sure you hold down the button for a few seconds.

2. To shut down the power, you will turn the main power switch to the left. The main power switch is located on the front panel of the instrument (Figure 4).

3. Once the power to the instrument if off, you can shut down power to the computer.

- Close the XRF core scanner software and any programs that are open on the desktop.
  - On the new instrument, you will need to close the scanner control software.
- Click on the "start" button on the desktop, and press "shut down".

4. Wait a full minute.

5. You will start the computer up before turning back on the power for the instrument.

- Once the computer is on you will log back into the account (username: DAQ/ password: DAQ).
- Open up the XRF software.
  - For the new instrument, you will need to open the scanner control software along with the XRF software.

Figure 4: Main power switch for the XRF scanner. To shut off power to the machine, turn the switch to the left. To power switch to the right to restore power to the instrument.

6. Turn the main switch to the right to restore power to the instrument (Figure 4). The arrow should be facing upwards. The instrument startup may take a few minutes.

- If you completed the hard reset on the old instrument, you have to follow a few extra steps to navigate back to the control screen on the touch panel.
  1. Wait a few minutes for the computer within the instrument to start up.
  2. Once the old instrument starts back up, the touch panel screen will display "Avaatech XRF Core Scanner" logo.
  3. You will have to press the black bar on the middle of the screen to return to the scanner control screen (Figure 5).

To recover from an emergency stop follow steps 7-12:

- - NOTE: To recover from hitting the “Emergency Stop” button, you will have to pull the “Emergency Stop” button away from the instrument.

7. Once power is restored to the instrument you will notice that the error message symbol and a stop sign appear in the upper right corner of the screen. The error messages have to be cleared before functionality is fully restored (Figure 5).

Figure 5: The scanner control screens for the old (on the left) and new (on the right) instrument. On the old instrument, press the black bar to return to the control screen. Also, you will notice in the upper right corner of the scanner control screen's that the error message symbol and a stop sign appear after shutting down the instrument or hitting the emergency stop button. Before you can restore functionality to the instruments you must remove the error messages.

8. On the old instrument to clear the "stop sign" you will have to press the "reset emergency stop" button on the front of the instrument. For the new instrument, you will have to press the "reset error" and "reset cycle" buttons to clear the error message and emergency stop message. There is not a physical "reset emergency stop" button on the instrument.

9. To remove the error messages press the “reset error” and “reset cycle” buttons (Figure 6). The error indicator symbol should disappear.

10. Double check that the instrument is in remote mode. You should see a computer icon in the upper, left corner of the scanner control screen. If you do not see the computer icon, the machine is in "local mode". Press the "remote mode" button.

Figure 6: Press the “Reset Error” and “Reset Cycle” button to remove the error message from the main control panel. Once you have cleared the error message the error symbol in the upper, right-hand corner will disappear.

11. Return to the computer.

If you restarted and/or shut down the computer you will have to reconnect the XRF Core Scanner Program to the instrument. Go to the desktop and open the XRF Core Scanner Program.
- Press the “connect to scanner” button (Figure 7).

Figure 7: The XRF Core Scanner Program. Click on the scanner connection button to reconnect the software with the instrument. The connection may take a few minutes.

- A pop up window will appear after clicking on the "connect to scanner" button. (Figure 8). Reconnecting the software and the instrument may take a few minutes. If you have a good connection, two green check marks will appear. If you see a red "X" there is an problem with the connection between the software and instrument. Double check the instrument is in "remote mode" and not "local mode". One common mistake is the instrument is left in "local mode" which prevents the software and instrument from communicating.
  - If the problem continues, contact the Lab Manager and/or the Technician.

Figure 8: Click on the "connect to scanner" button in the XRF Core Scanner Program. A connection screen will appear. The software will attempt to connect with the MCA and the instrument. Depending if the software is able to connect with the instrument you will either see a red "X" or two green check marks.

12. If you have a good connection and the instrument is properly working, you can resume measurements!

Z-axis Error or Prism Not Low Error

Explanation of Error

The Avaatech XRF Core Scanner motion control software and hardware is designed to prevent the instrument from damaging itself, should the prism position be inaccurate. Consequently, if the limit switch is engaged when the instrument receives a "move" order, it will throw a Z-axis error. The instrument won't move to the next designated position.

How to Fix the Error

In order to clear the error, the instrument's limit switch must be disengaged. Use the following procedures to clear the Z-axis or the Prism Not Low Error (Error #2098).

Method One:

1. Place the instrument in "Local" control mode by clicking on the "local" button found in the scanner control panel (Figure 9).

Figure 9: Click on the "local" control button in the XRF scanner control panel. When the scanner is in "local" control you will notice a hand symbol in the upper left-hand corner of the control screen.

2. To navigate to the control servo screen click on the "Servo" button (Figure 10). In the control servo window, you will be able to change the destination of the carriage.

Figure 10: Press the "Servo" button on the main control screen to navigate to the control servo screen.

3. For the new instrument, to change the position of the carriage you can press the "INIT" button or enter in the desired destination for the carriage into the destination field.

4. For the old instrument, press the arrow button in the lower right corner of the screen (Figure 11).

This takes you to the "Jog Servo Axis" screen.

Figure 11: Old instruments's Control Servo Axis screen. Used to control the position of the carriage. By entering in a "destination" value and pressing the "GoTo" button you can move the carriage to a new position. Pressing the "Init" button will return the carriage to the home or start position.

5. Press the up arrow in the upper left corner above the word "Jog" several times (Figure 12).

Each time you press the “jog” button it will raise the carriage only a few tenths of a millimeter. This should raise the instrument off the core surface. Once the carriage is off the core surface, the error message should clear itself off of the machine.

6. On the old instrument, to return to the main control screen press the top, middle bar on the touchscreen.

Figure 12: Old instrument's Jog Servo Axis screen, which controls the position of the carriage.

7. You will want to check that the error message has cleared itself. If the error message symbol still appears on the main screen, then you will need to press the "Reset Error" button (Figure 6).

8. Before resuming measurements, you will need to return the instrument to remote control (Figure 13).

9. Reconnect the XRF scanner software and the instrument, by clicking on the "connect to scanner" button in the XRF Core Scanner Program (Figure 7).

10. Resume Measurements!

***If method one does not fix the problem, follow the procedure for method two or contact the Lab Manager or Technician.

Figure 13: To be able to resume measurements on the instruments, you will need to return the instrument to "Remote" mode. Remote mode allows for the computer software and the instrument to communicate.

Method Two:

1. Place the instrument in Local control (Figure 9) and open the door.

2. Lower the core section away from the detector using the mounting devices.

3. Press the "Servo" button (Figure 10).

4. This takes you to the "Control Servo Axis" screen. Enter a destination value (e.g., 800) in the destination field (Figure 14).

- Once you have entered in the destination value, press the "Go To" button on the control servo axis screen (Figure 14). Which should raise the carriage and move it to the selected position.
- You can also press the “INIT” button to take the carriage back to the home position instead of moving the carriage to a certain destination. The goal is to be able to move the carriage off the core to resume measurements (Figure 14).

Figure 14: The servo axis control panel will allow you to move the XRF carriage assembly to a different position. Either by pressing the "Init" button or entering a "Destination" value. Then you will have to press the "GoTo" button to instruct the instrument to move the carriage.

5. Once the carriage has moved off the core, you should be able to clear the error message. To remove the error message, go back to the main menu and press the "Reset Error" button and "Reset Cycle" button (Figure 6).

6. Place instrument back in Remote control (Figure 13).

7. Resume measurements!

Interlock Error

Explanation of Error

One of the internal safety mechanisms of the instruments is an interlock system that prevents the door from being open while the source is turned on. If you shut the door and the interlocks do not fully engage an "interlock" error will occur. Making it impossible to turn on the x-rays and start scanning a core section. (More common on XRF1)

**First: Try clearing the error by clicking reset error, then reset cycle, from the XRF GUI (Figure 6). This may clear up any issues relating to this error right away, but if not, continue the full procedures below.

How to Fix the Error

1. Open the instrument door and close the door again to make sure the door is fully closed. Always make sure to hold the “close door” button until the door is fully closed.

When the door is open you can check to see if the safety interlocks are sticking and/or ask the Lab Manager or technician to have a look at the door interlocks.
At times the interlocks become stuck on the old instrument. If this occurs you will manually have to push the door to engage the interlocks.

2. Once the XRF door shuts again and the interlock light comes back on the problem should not persist. If the error message symbol does not disappear you will have to press “Reset error” and “Reset Cycle’ (Figure 6).

3. Resume measurements!

Connection Lost Between Scanner and Computer

Explanation of Error

At the beginning of a scan, there is a possibility that the software and the hardware components of the instruments will stop communicating. Likely you will notice that this problem because you will receive zero counts and/or the spectrum will not be updating after you have started a new run (Figure 15). Once you start a run, it is important to make sure the y-axis is updating and you are acquiring new spectrum.

Figure 15: The XRF Core Scanner Program. If the scanning software and the instrument is unable to communicate the spectrum will either show zero counts, as the image above, or will show the last spectrum successfully collected. However, the spectrum will not update and the software will not collect any new data.

How to Fix the Error:

1. Check to see the instrument is in "remote mode".

If the instrument is in "Local Mode" change the instrument to "Remote Mode" (Figure 13).
You will have to reconnect the XRF Core Scanner Program to the instrument by clicking the "connect to scanner" button (Figure 7).

2. After pressing the "connect to scanner" icon, a pop-up window will be displayed in the XRF Core Scanner Program (Figure 8). Two green check marks will appear if the software is able to communicate with the scanner. However, if there is a problem a red "X" will appear indicating that the software cannot connect to the MCA or to the instrument.

Double check that the machine is in "Remote Mode"!
If the XRF Core Scanner Software is unable to connect to the MCA or the instrument complete a hard reset of the system to fix the issue. You will have to review how to "Complete a Hard Reset or Recover from an Emergency Shutdown" for directions.

3. Resume Measurements!

If the problem persists contact the lab manager and/or technician for further assistance. The lack of communication between the software and the instrument may be due to another problem that acquires assistance.

XRF Software Freezing

Explanation of Error

After starting a run, you may notice that the core-scanning program continues to try to connect to the XRF scanner and is not successful. In the scanner status panel, you will notice an hourglass that does not go away, and the current activity will not change. There is a miscommunication between the XRF core scanner program and the machine. Sometimes when the XRF scanner program sends commands to the machine, the command will get “stuck” in the cache causing the software to freeze and unable to send any new commands to the machine. You may be able to close the software and the program will go back to working properly. However, if restarting the software does not work follow the methods bellow on how to fix the error.

How to Fix the Error

1. Use Ctrl+Alt+Delete to close the XRF computer software.

Click on the “Start Task Manager” button.
Select XRF Software in the task panel.
Click “End Task”.
Once you have closed out of the XRF Core Scanner Software you will need to open program, found on the desktop, and connect the software with the instrument. Press the "connect to scanner" button in the software. (Figure 7).

2. Go to the control panel for the XRF. Change the machine from “Remote mode” to “Local Mode”. By changing the mode that the XRF is running in, there is a possibility it will clear the cache for the machine, and allow the software and the machine to reconnect.

3. If you continue to have problems with the software-reconnecting follow these steps:

Close all of the programs open on the computer.
Close the XRF software by following the Ctrl+Alt+Delete method. Once the software is closed shut down the computer.
Complete a hard reset of the XRF.
Review hard reset instructions above if you have any questions regarding the process and recovery.
Reconnect the software to the XRF (Figure 7).

For additional assistance, contact the lab manager and/or technician.

XRF1 Mechanical Issues (Uncommon)

Explanation of Error

Due to the aging of XRF1 (older model), we noticed more mechanical issues related to the detector prism area. (1) First issue that was noticed was the decreasing overall throughput values seen in the standards, where a downward trend is visibly seen and continued to trend down as scanning continued. The result of this problem was caused by a mechanical failure due to a loose servo motor, causing drag/lag on the gear operations of the filter screen wheel which resulted in the filter window to be misaligned with the x-ray tube slits (Figure 17). Slowly but surely, the gears connected to the servo motor would get of sync for the no-filter screen option, resulting in a further decrease of overall throughput. There is no indication of this failure except the noticeable drift that is seen in the standards. (2) The second issue was noticed soon after the run was started. The track system did not move, and current activity was stuck on the "initializing scanner" message. Upon further inspection, the message panel on the XRF Aquisition software denoted that the function of the x-ray tubes was fine, but the window slit operations has failed, causing a freeze on XRF operations for that section. The software will continue to try and connect to the slit operation module but is not able to.

Figure 17. Visible misalignment of the no-filter window on the filter wheel/gear, behind the metal slits, both of which are attached to the x-ray tubes.

Figure 18. Proper alignment of the filter wheel/gear, that is flush with the slit window parameters.

How to Fix the Error

Issue (1). The allen screw holding the servo motor has become loose and needs to be re-tightened (Only the XRF Lab manager should do this).

First, inspect that the "no-filter" window is flush with the outbound window slits on the x-ray tubes (Figure 18).
- This requires taking apart the detector/prism shoulder, off the x-ray tubes.
Second, the servo motor needs to be re-seated, flush with the surface it is screwed on.
Then, the allen screw that is holding the servo motor in place, needs to be tightened.
Make sure the gears are aligned and operational with the no-filter window visible on the outbound window slits.
Rerun standards to see if drift in the measurements is corrected.

Issue (2). The window slits need to be jogged, similarly to the z-axis prism error above.

First, stop the scan by clicking the "square" button next to the "play" button in the XRF acquisition software, then put the machine on Local control through the WinVNC Software (Figure 9, old scanner).
- Note: The x-ray train may be in "step" mode, where the detector has landed and is attempting to measure that spot. If this is the case, go to the Servo menu and press the Init button to rehome the detector train.
In the same GUI, click on the Slit button, situated within the blue background space (Figure 9).
In the slit screen, there are four arrow buttons that you can push to jog the slit windows. Click on the arrow that is pointing up, once, and see if the machine responds. You should hear mechanical whirring and see the numbers change, signifying changes in the slit parameters.
- If the slits do not jog manually with the arrows, try using the init button to see if the slits close. They will not open back up, but this is okay. Although closed, they have been "jogged", and should be operational for the scan.
Once confirming the window slits are working, continuing jogging the window slits a few more times, then click on the Init button, which will reposition the window slit size to its original location.
Go back to the main menu and put the control back to Remote, and resume scanning.
- The setup will take a few seconds longer as the slits reposition to the set parameter (1x1.2 cm)
Ensure that you are getting decent throughput during scanning.
If this doesn't work, contact the lab manager.

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