RIGOL MHO98 and MHO900 Oscilloscope Series

[0xdeadbeef]

the MHO98 comes with a Wi-Fi dongle.
I couldn't find any information about this in the data sheet.
Do other Rigol devices also come with a dongle like this? For example, the MHO900, DHO800 or DHO900?

AFAIK, this was a bonus only for the MHO98 version. Not an expensive bonus anyway.
It was probably mentioned somewhere, but the chipset should be something like RTL8821CU.
But it was also reported that the TP-Link WN725N with an RTL8188 chipset will work (better).

[rnelectro]

Hello,

I received a Rigol WiFi dongle with the purchase of the standard version of the MHO934 (bought in Poland from the NDN store).
The dongle is based specifically on the Realtek 8821CU 802.11AC USB chip.

Additionally, I noticed that the Rigol WiFi dongle, when used simultaneously with a 2.4GHz PC mouse dongle, causes the oscilloscope to freeze on certain USB hubs—especially those that have a microSD card slot. However, on hubs without a microSD card slot, it works without any problems.

Regards
rnelectro

[norbert.kiszka]

I noticed that the Rigol WiFi dongle, when used simultaneously with a 2.4GHz PC mouse dongle, causes the oscilloscope to freeze on certain USB hubs—especially those that have a microSD card slot. However, on hubs without a microSD card slot, it works without any problems.

Android log (logcat) and kernel log (dmesg) may show the cause of it. If this ends up as a kernel panic (something like BSOD in Windows), only useful data will be only in UART output.

[tonyalbus]

Yeps.. MHO98  with stick reporting as: Realtek 8821CU in windows

[rnelectro]

Hello Norbert

Thank you for the information. However, I haven't tried disassembling the oscilloscope yet, so I don't have access to the UART (I assume there's no other way to view the UART log without disassembly).

The freeze means the screen goes completely dark and the oscilloscope doesn't respond. The only way to fix it is to turn it off and on without the hub connected.

Regards

[tonyalbus]

Maybe the Hub and the devices together are taking to much current from the USB port, have you tried a powered usb hub?

[rnelectro]

Maybe the Hub and the devices together are taking to much current from the USB port, have you tried a powered usb hub?

Yes, this could be the cause of the problem, as disconnecting the Wi-Fi dongle or mouse dongle from the hub with an SD card slot eliminates the problem, but connecting both at the same time causes the device to freeze.


I measured the current using an FNB58 USB meter, and connecting two dongles and a hub with an SD card simultaneously causes the freeze, even though the static load is relatively small, i.e., 51 mA (WiFi is inactive, and the mouse also doesn't work because it's connected through the FNB58 meter).

The problem may be due to a temporary overload (e.g., too large a total capacitance - e.g., several 10uF capacitors), and perhaps a super high-speed protection device tripping, or the devices are simply interfering with each other.

According to the specifications, the USB 2.0 port's current capacity is 500 mA.


Regards

[PinheadBE]

Mîne was delivered today
#1982

[norbert.kiszka]

Thank you for the information. However, I haven't tried disassembling the oscilloscope yet, so I don't have access to the UART (I assume there's no other way to view the UART log without disassembly).

The freeze means the screen goes completely dark and the oscilloscope doesn't respond. The only way to fix it is to turn it off and on without the hub connected.

If Your scope is younger than about one-two months, it's better to wait. Most hardware failures happens shortly after receiving the scope.

MHO900 has UART socket at the top left corner (when looking at the front), same as DHO800/900. Personally I bent those goldpins and I did a cut in the plastic. So whenever I need to listen to UART or change SD card, I don't need to remove the back case.

[rnelectro]

Thank you for the information. However, I haven't tried disassembling the oscilloscope yet, so I don't have access to the UART (I assume there's no other way to view the UART log without disassembly).

The freeze means the screen goes completely dark and the oscilloscope doesn't respond. The only way to fix it is to turn it off and on without the hub connected.

If Your scope is younger than about one-two months, it's better to wait. Most hardware failures happens shortly after receiving the scope.

MHO900 has UART socket at the top left corner (when looking at the front), same as DHO800/900. Personally I bent those goldpins and I did a cut in the plastic. So whenever I need to listen to UART or change SD card, I don't need to remove the back case.

Exactly, most failures occur at the very beginning of use.

However, I don't think it's a hardware failure because everything works as long as I'm not using a hub with a Micro SD card controller (at least the one I have).

Next week, I'll borrow another hub and test it.

I think other users will test it on their hubs at the same time and see what happens.

PS. I work in the quality department in the electrical power industry, so I have firsthand information based on comprehensive analyses 

[egonotto]

Hello,

The record function responds significantly faster than the DHO1074 did at the time. The latter was unable to record segments with a 5 ms interval without gaps.

The MHO98 copes well with an interval of 1.25 us.
 
Kind regards,
egonotto

[tonyalbus]

Did some testing with USB-Hubs.
Tried a nice self-powered USB 2.0 .. HID and storage works, but WiFi not.
Using an older USB external powered Hub, it all works.

It seems the power output from teh Rigol is very low, it can not power my thumbdrive, wifi and touchscreen(mouse) at the same time.
That is a real pitty i had a very nice small hub.

[crysti]

Did some testing with USB-Hubs.
Tried a nice self-powered USB 2.0 .. HID and storage works, but WiFi not.
Using an older USB external powered Hub, it all works.

It seems the power output from teh Rigol is very low, it can not power my thumbdrive, wifi and touchscreen(mouse) at the same time.
That is a real pitty i had a very nice small hub.

Could you please provide the USB Vendor ID (VID) and Product ID (PID) for the Rigol Wi-Fi dongle, as well as any additional technical details required to identify it correctly under Windows or Linux?

[egonotto]

Hello,

VID_0BDA  PID_C820

Strangely enough, the USB dongle was already plugged into the MHO98 when I received the device.

When I plugged the dongle into my PC, the Device Manager showed that my PC Bluetooth device did not have a working driver, but the Rigol dongle I had plugged in had a working driver.
I then reinstalled the Intel driver for my PC Bluetooth device, and now the Rigol (Realtek) dongle no longer has a driver.

Best regards
egonotto

[PinheadBE]

Strangely enough, the USB dongle was already plugged into the MHO98 when I received the device.

Same here

[eurofox]

Hello,

VID_0BDA  PID_C820

Strangely enough, the USB dongle was already plugged into the MHO98 when I received the device.

When I plugged the dongle into my PC, the Device Manager showed that my PC Bluetooth device did not have a working driver, but the Rigol dongle I had plugged in had a working driver.
I then reinstalled the Intel driver for my PC Bluetooth device, and now the Rigol (Realtek) dongle no longer has a driver.

Best regards
egonotto

​Maybe your guy's got the first Chinese copies of this legendary oscilloscope 

[dzebrys]

Hello Norbert

Thank you for the information. However, I haven't tried disassembling the oscilloscope yet, so I don't have access to the UART (I assume there's no other way to view the UART log without disassembly).

The freeze means the screen goes completely dark and the oscilloscope doesn't respond. The only way to fix it is to turn it off and on without the hub connected.

Regards

for logcat or dmesg all u need is plug eth cable and use adb
uart is needed when u have boot issues before adb service is up.

br/Piotr

[norbert.kiszka]

Hello Norbert

Thank you for the information. However, I haven't tried disassembling the oscilloscope yet, so I don't have access to the UART (I assume there's no other way to view the UART log without disassembly).

The freeze means the screen goes completely dark and the oscilloscope doesn't respond. The only way to fix it is to turn it off and on without the hub connected.

Regards

for logcat or dmesg all u need is plug eth cable and use adb
uart is needed when u have boot issues before adb service is up.

br/Piotr

There is no access via adb, when kernel panic() is executed. It stops all processes, sends debugging info to the "console" and enters infinite loop. Eventually it can call CPU reset, which is the same as reboot.

Almost same thing when CPU will stop code execution for any reason. Almost, because often it will not produce any debugging info.