ASI178MC does not work on ASIAIR Plus USB 3.0 ports

jasuastro

Hello everone, my ASI178MC does not work on ASIAIR Plus USB 3.0 ports. Error message: Please check the connection of the Main Camera and retry. But my ASI120MC-S works just fine on ASIAIR Plus USB 3.0 ports.
The ASI178MC only works on ASIAIR Plus USB 2.0 ports. And the ASI178MC works fine on a notebook with USB 3.0 ports!?
I can rule out an insufficient or bad power supply. The power supplies I tested have 6 and 8 Ampere (72/96 watt) outputs.
ASIAIR Plus Firmware: 2.0(10.46)
Who can help me?![

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w7ay

jasuastro The ASI178MC only works on ASIAIR Plus USB 2.0 ports.

Actually, it is probably the case that your particular copy of the ASI178MC does not work on your particular copy of the ASIAIR, with the current USB cable. The USB implementation on ZWO's products are finicky (see my post about it in the last day or two).

A USB 2.0 Type A connector (like on the ASIAIR) have 4 pins (power ground and a pair of half duplex pins). Which are easily visible to the eye.

If you look deep inside a USB 3.0 Type A connector (baby blue plastic insert) you will (barely, with a flashlight) see 5 extra pins. These are for two new extra high speed full duplex data pairs (one for each data direction), plus a ground drain (for the USB 3 cable shield).

Typically, deep down in the USB software stack, it will try to establish connection to a device first on USB 2. And if it finds that the device will support USB 3, will then switch the data bus from the half duplex wire pair over to the two full duplex data pairs.

So, it is even possible that the camera will be visible (on USB 2 data pair), but then malfunction (on USB 3 data pair). I.e., it might connect to the camera and then fail transferring data.

When you connect the camera to the USB 2 port, it obviously will work, since ASIAIR will be using the original 4 pins on USB 2 and signaling at a slower data rate and therefore not hit any kind of design margins.

The defect could be in the extra 5 USB-3 wires at ASIAIR, on the two connectors of the ends of the cable, or at the camera. If other devices work at full speed on the ASIAIR USB 3 ports, and using the same cable, then the camera's USB 3 port is weakest point.

Because ZWO's USB ports are not designed with proper margins, it is possible that you will find some USB 3 cable that will make the camera suddenly work, even though your current cable does not work.

Test with the shortest USB 3 cable that allows you to reach between the camera and the ASIAIR. Use a USB cable that is shielded and with thick AWG wires. They may be thick and ugly, but they work better. Never use the USB cables that come in the ZWO boxes.

If a 1 foot long thick USB 3 cable still does not work, return the camera to the dealer for replacement. If you have a good rapport with your dealer, they will even exchange the camera if it works with some cable and not others (indicating that it works but marginally).

Chen

jasuastro

Hi Chen, thank you very much for your quick and very detailed reply!
In fact my ASI178MC does not work with the shown shorter USB3.0 cable either.
Since the ASI178MC is only 5 months old, I would prefer to return the CAM as a warranty case. My only question now is whether the USB3.0 transfer will work with the ASI178MC replacement.
Can the ASIAIR Plus be ruled out as a source of error for sure, since the CAM works on a notebook via USB3.0??

Thanks again for all your efforts!
Jan![
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w7ay

jasuastro Can the ASIAIR Plus be ruled out as a source of error for sure, since the CAM works on a notebook via USB3.0??

Any USB implementation by ZWO (all their cameras, and ASIAIR since the second generation onwards -- the first generation used real Raspberry Pi 3 card) are not well engineered. That is why ZWO keeps asking their customers to test with different cables, with the hope that one of them will bring the margin (voltage not perfectly 5.1V, mismatch in characteristic impedance of the USB port and the cable, timing of the signaling pulses, temperature, etc) where the pair together will "just" work.

In your case, I suspect that your ASIAIR port is the worse of the two (ASIAIR or ASI178) since your camera works with any computer and any cable, just not with the ASIAIR.

I would try to exchange the camera, and if it still fails to connect with the ASIAIR, then you need to do something about your ASIAIR (like the local landfill).

If your ASIAIR is still new, you may be able to get your dealer to swap that too... in fact, many friendly small dealers will be willing to test the combination of a new camera and new ASIAIR before sending the replacements to you.

BTW, do you have any other USB 3 devices that you can test on the ASIAIR USB 3 port? For example, a different USB 3 camera, or a USB 3 SSD drive (or very fast flash drives) to test if the file transfer speed is at USB 3 speeds or at USB 2 speeds. Right off the top of my head, I cannot right now think of what other USB 3 device you can test the ASIAIR port with, since the ASIAIR supports so few devices.

Chen

jasuastro

Hi Chen, thanks for the great solution ideas as well.
I would like to confirm again that my ASI120MC-S USB3.0 CAM works on the USB3.0 ports of the ASIAIR Plus.
I particularly like your idea of having my dealer test the combination of camera and ASIAIR Plus.
However, Teleskop-Service is not a small retailer.
Finally, when my problem will be solved in a few weeks, I will contact you again. You can count on that ;-)
Kind regards
Jan

jasuastro

Hi Chen,
here is my feedback: My dealer was able to reproduce the error on one of his ASIAIRPLUS: the error is caused by the ASI178MC.
Unfortunately, the error analysis of the dealer took a long time, because at first only Logfiles should be transferred to ZWO for evaluation purposes, but these did not contain any significant entries. Further delays were caused by the fact that both devices were not allowed to be returned at the same time. And there were further misunderstandings about the test scenario of testing at least one minute in video mode...

Unfortunately, it is now the case that I have to expect a waiting time of 15 weeks, since my ASI178MC is to be repaired directly in China and the shipping had to be done by ship?!?

6 weeks by ship to China
3 weeks processing time at ZWO
6 weeks by ship back to Germany
plus customs clearance problems?

This procedure is very customer unfriendly, since the ASI178MC is still on sale.

However, I would like to thank you again for your support and your time. - THANK YOU VERY MUCH!

Kind regards
Jan

w7ay

jasuastro since my ASI178MC is to be repaired directly in China

Glad TS is helping you, Jan.

The problem is that once "repaired," the camera may still not work for your situation. The problem appears to lie in the USB hardware design for not just the camera end, but also the ASIAIR end (ever since the second generation ASIAIR -- before the third generation ASIAIR, the USB hardware was done by Raspberry Pi).

There appears to be very little design margins in their USB hardware. And if the components (or temperature, or time) moves the operating point of one device away from another device, the two devices will stop talking to one another. This is why you see ZWO response on this forum to be try different cables and power supply voltages, in the hope that some combination will cause a workable match between the devices again.

https://www.planetanalog.com/design-margins-in-analog-digital/

The way I have solved the problem with the ASIAIR is to use a powered hub, through a very short USB cable. All other devices connect to this hub, and not to the ASIAIR. Only the hub is connected to the ASIAIR. That solves half of the problem. I still have one pancake camera (used for guiding) that would not work with USB 3 when the length of the cable exceeds 0.5 m. So, I have marked that camera for use only with USB 2 Type B cables.

When I use INDIGO Sky (Raspberry Pi 4), I could use any of the Raspberry Pi's USB ports.

I also do not use any of the camera hubs. I have a "pro" camera that would not consistently work with a filter wheel. So, all of my devices are connected to the hub, punkt.

Chen