Having issues with channel shutdowns? Watch this video for a guide on how to check log files within the LifeTest Monitor status screen and interpret results.
Why did my Channel Shut Down? How to Check Log Files and Interpret Results:
The screen we’re seeing here is the LifeTest Monitor screen. This is the status screen you’ll periodically check when you have a test up and running.
It's a real-time readout of the number of channels that are running, and the data being recorded by the system.
The first thing you notice is that there are some differences in the channel color codes. Nominally, a white channel is a good sign, indicating everything is running and storing data as you would expect.
Currently on this screen, you see a few different instances, where there are color codes indicating an issue with that channel.
To see what the different color codes mean, you can right-click in the background of the LifeTest Monitor screen and select "View Color Codes."
That will bring up what the different iterations are here.
Checking the Auto Sequence Log File:
If you are running a test in AutoSequence Mode, the first step in troubleshooting this issue is to check the auto sequence log file.
To begin, click to highlight and select the affected channel, and you'll see the channel number displayed in this field.
Next, pick "view" in the menu bar and select auto sequence log file. This brings up a time stamped log of the major events that have happened to this channel – starting from when you first turned on the channel, down to the last entry, which will be the last event that happened. We see here, the most recent event is "shutdown, auto sequence stopped, cannot activate channel, hard failure".
In our system, a hard failure means this channel hit some sort of limit defined by the user. For example, you may run the part until it degrades to a certain amount, and then it hit the limit and shut down, or the part might have failed catastrophically and needs to be replaced.
The next step to investigate the issue is to close the auto sequence log file window and can come back to the life test monitor. Now the color coding can help key in on what the parameter was that experienced the channel to go into that state.
We see the column here that's red is the Bias_1 current, I_Bias1 is the Bias_1 current. So, the grid here is telling us that that's the parameter that experienced the hard failure.
The current screen shows a global view of every channel, for a more detailed look at a specific channel - go to the view menu and select single channel.
This view focuses on just a single channel – in this case just channel 4's info is shown in tabular format. And this shows what the min and max limits are for each parameter. You can see here for I_Bias1, this hard limit had to have exceeded this min value or max value. So this is a clue that, "Oh, okay, I see that I'm below my minimum value so the channel shut down for this reason.
With that known, you can decide how to best proceed at this point. Likely your part has failed and needs to be removed from the system and a replacement part could installed. Or you could potentially adjust these limits and resume the test with new, adjusted limits in place.
Sometimes a little more investigation is needed to identify the issue. Looking at channel 14, you can see that is not showing the nominal color code, but it doesn't have the obvious indicator of the red that channel 4 did.
You first repeat the process with checking the auto sequence log file. Highlight channel 14, click view, auto sequence log file. By going down to the very last entry you’ll find - "auto sequence stopped, auto start cycle, set RF level failed."
So it failed to set the RF, which is more indicative of a possible issue with the system or the settings rather than the device itself that your testing.
This gives us some info, but it's not really enough to draw a conclusion as to why the channel shut down.
What we can do now is make note of this timestamp, the date of 11-21 and the text (highlight timestamp on screen) and go into the system log files. Close this window and return to main LifeTest Monitor screen.
Checking System Log File:
The system log file is the more detailed record of what’s happening in the system. It’s capturing pretty much every background transaction from the software and recording that to the system log file. It provides a much more detailed look than the auto sequence log file.
Navigate to the view menu and select System Log Files. You’ll see that this contains a lot more information, so what you can do is scroll to that specific timestamp noted from the auto sequence log file, or you can search for a keyword.
Hit Control-F on your keyboard to bring up the “Find Text” box. Enter “failed" and press OK.
That will typically bring you to the instance where the channel shut down. You can see we're at that 11-21, 1:37 AM timestamp.
What this tells us is that the channel shut down for failing to set RF drive to channel 14 and it eventually timed out while trying to set RF drive. So, one of the settings that the system has in the configuration is that there's a time-out period of 300 seconds, so if the system fails to set RF drive through a particular channel for more than five minutes, it will shut down that channel.
The reason being, so that it doesn't cause an infinite loop where it's trying to set RF drive but failing. At this point you will need to determine if there is a hardware or configuration/settings issue
Determining if it’s a configuration or hardware issue
One conclusion you could draw from this, is that there might be a hardware issue with this channel. If so, that requires some additional troubleshooting before this channel can be used again. For more information, please view the other videos on hardware related troubleshooting.
You may also determine if it’s a system settings issue – in this case it may have timed out because it was trying to set too fine a level for RF drive. The system was trying to resolve an iteration level that really was unrealistic and then it eventually timed out.
Adjusting the setting configuration is one possible solution that can be done in the software with edit iteration control menu.
Adjusting Iteration Levels
Close out of the log file window, and go to edit menu, and select "Iteration Control."
This screen allows you to adjust what the acceptable target values are for certain parameters. You can select the parameter you want to adjust from the dropdown menu at the top of the control panel
For example, you can select “Set Bias1”, then set the what acceptable range is for that, and that's plus or minus 20 millivolts, as what's listed here. Then you’ll see the time-out window as well, how long it will attempt to set that range before it shuts down and leaves you in a state where the channel is stopped.
Going back to the RF level issue, select “Set RF Levels”
You will see that channel 14 is set to .1 DB here, which is the unit for RF power. You can potentially change that value to open up the window – right-click, select change values, and then change that from 0.1 to 0.2, then save and exit.
At this point, you can retest by restarting the channel and wait for the necessary period of time to see if the channel runs successfully.
If you experience another failure, the problem is most likely a hardware issue and you will need to proceed to the troubleshooting hardware videos or if you still need assistance, please SUBMIT A SUPPORT TICKET