Hi Craig Todd
I understand that you using ThingSpeak and are encountering an issue where the Field Gauge Widget(dial) appears blank, showing just the outline but nothing inside the window. YOu are also wondering if guages are still supported.
Yes, Field Guage is supported. Since Simulink 7.3 (R2006b), the product has been referred to as Gauges Blockset and there are no more dials. The latest version of this blockset is available with Simulink 7.9 (R2012a).
One possible explaination for the issues might be that the gauge widgets created in the private view contain spaces for the user to add JavaScript in it. For security reasons, users are not allowed to run JavaScript in a shared channel to prevent security vulnerabilities that can be exploited with JavaScript. Alternatively, you can make use of MATLAB Visualizations to represent data. This visualization can be shared in either private or public view, as all the JavaScript involved is under the hood.
If you have more questions related to this, do get in touch with the MathWorks Technical Support team at: https://www.mathworks.com/support/contact_us.html
For more information related to Field Gauge, please refer the following documentation link: https://www.mathworks.com/help/thingspeak/channel_display_widgets.html
Hope this helps!
Regards,
Arun