I just got a new Logic MSO and I noticed that when I use it for only 15 minutes or so, it becomes hot to the touch. How hot should I expect this to become, or how hot is too hot and I should return it?
@rickwilsonconsulting Sorry for the trouble with that! I’m running an MSO capture now (12-bit, 100MHz model, 30min and counting, 1 GS/s on 4x analog, 4x derived digital, and 8x digital channels).
So far, the metallic enclosure is warm to the touch (i.e. I can comfortable place my hand on it), but not hot.
Which specific Logic MSO model do you own, and is this similar to what you are experiencing? We can easily process an MSO replacement for you in case we find out your unit is faulty as well. Hope to learn more!
Once warmed up, the touch temperature of the unit should be around 90 degrees F (32 C).
Also, the unit is running it’s own temperature management. The fans will get pretty loud if it’s struggling to keep cool, and the unit will automatically enter reset and power consumption is dramatically reduced if it gets too hot.
We don’t have a proper feature for this yet, but you can enable developer mode in the software and it will show the internal temperature sensor data. Please follow the procedure below, and send us the temperature data after running the device for at least 15 minutes.
Regarding returns, the data collected below should tell us pretty quickly if there is a problem. Also, under normal use in a room temperature room, the fans should be fairly quiet. If you regularly hear the fans running at maximum power, that would indicate either there is a problem with the device or you’re using in an environment that’s too hot. When the device powers up, you will hear the fan spin up higher than normal operation. Next time you power up the device, take note of the fan volume during initialization and let us know if you hear it reach that level again. (This is not the maximum fan speed, but it’s louder than normal operation)
Procedure To Display Temperature Data
If you’re on Windows or Linux, press Ctrl+Alt+Shift+C all at the same time. This activates the developer features. This will also open the developer sidebar. If you’re using Mac, press Ctrl+Option+Shift+C.
In the developer sidebar, enable “Developer Actions” > “Feature Overrides” > “Display MSO Debug” (switch it on)
Then in the bottom bar, a new item will be added. Clicking it shows all the internal temperatures for the unit:
Here are the current temperatures from my 4 channel unit:
This option stays enabled even if you restart the app. It will pulse blue when the device is below temperature, and it will pulse red if the device is above temperature.
The fan control system tries to maintain the AFE temperature at 50 degrees Celsius. (Note, in the future we may ship new 2 channel units which target 40 degrees Celsius.)
Thanks for the help, I guess it is working as expected.
I measured the outside temperature at 33.5C.
Thanks again for the help.
Thanks @rickwilsonconsulting, we just discussed this internally and we’re planning on adding details about this in the software for all end users, since I’m sure you’re not the only one with this concern.
One of the design decisions for Logic MSO was choosing the internal operating temperature. To maintain calibration accuracy, the device needs to be held at a very narrow temperature range. Using a higher operating temperature allows us to run the fans slower and lets the device maintain temperature in hotter environments, but at the expense of higher touch temperatures and longer warmup times. Additionally, we need to keep component longevity in mind.
This is currently just documented in the datasheet, but like all bench scopes (that we’re aware of), the calibration accuracy of the device only applies once the device has warmed up. The calibration error when cold is pretty small, but for measurements that require traceability, or when you need to push the limits of the device’s accuracy, waiting the warm up period is a necessity. We want to add a feature to the app to just display when it’s in range so you don’t need to use a timer or wait the worst-case 30 minute warmup period.