Dewe-101 Minitaur Questions
Hello, my company uses the Dewe-101 Minitaur for lab and field data acquisition. Overall we are happy with the product. I have a few questions regarding the capabilities of the unit, and best practices for field use.
1. When we use the Dewe-101 for vehicle testing, we use a 425 watt power inverter hooked to the vehicle's 12 volt battery to power the unit. We will also use this inverter to power our laptop. Should I use a larger inverter to power the Dewe-101 and the laptop when using them at the same time? Is drawing power from the 12v vehicle battery a recommended power source for the Dewe-101? I have been told in the past that insufficient power supply from an inverter can result in excessive noise in the data signal.
2. What are the limitations to the USB connections for the Dewe-101? I am preparing for an
upcoming test, and I would like to use two USB cameras to collect video data.
I’ve used a single USB camera in the past with no issues. I have spent the past
few days testing with two USB cameras, and sometimes both cameras work, and sometimes only 1 camera works. It's very inconsistent. Is this a
limitation to the Dewe-101 unit? Does Dewesoft offer a more sustainable product
to record video data?
Thank you very much.
in regards to point 1, 12 V is enough to power up a DEWE-101. The minimum required voltage is 6 V, of course, measured on the contacts of the connector to account for the voltage drop, so the inverter is not necessary. The inverter will also add some noise to the line, so you might benefit from removing it.
The limitations of the USB data transfer are mostly defined by the root hub arrangement. Since the Minitaur's 4 USB ports on the back all originate from one root hub, how you connect the cameras doesn't really matter in this case. I've hooked up two Logitech C920 directX cameras to the system and I see that the processor is what's causing issues. Since the PC is a little outdated, it can struggle a bit handle all of the operations.
You can do several things to decrease the load:
- Reduce the frame rate and/or the resolution of the video,
- Reduce the sync/async buffers,
- Minimize the calculation delay in settings,
- Decrease the acquisition/display update rates,
- Have a more minimal live display (fewer instruments, video scaling should be proportional)
A more suitable product for recording video would be a newer PC. We offer a new version of the Minitaur and we also have SBOX PC's which can be a standalone product or could be integrated with a customly designed Sirius slice.