New Zoyi multimeter+oscilloscopes - ZT-70xS, up to 50MHz/250MSps (nov 2022)

[Randy222]

Related to the charging part.
I got my 703S

Icon in screen is like already said, when on charger the icon toggles between charge icon and batt level icon.
However, in the manual it says the lighted power button will go dark when it's done charging. My batt icon shows the full 4 bars ("full") but power button is still red. Will let it charge for a bit to see what happens.

Given today's cots IC's for batt charging & management, I suspect the batt can't overcharge, but perhaps the logic implemented for icon and light is not 100%.

Update: the longer I leave it on charger the more the power buttons starts to flicker. Initially a very faint flicker, but 30min later the flicker is more obvious. My guess, bad implentation of a comparator, or the full-charge threshold is set wrong.

Is there a hidden menu to see current firmware version?
 

[ahakman]

I wouldn't say it's "hidden", other than that horizontally scrolling the menu wasn't obvious to me initially either until I glanced at the manual

Press "menu", press "right" 3 times, version is the right most entry.
If you press F4 (the soft key under version), I get
Serial Num:
xxxxxxxx
Boot:
V1.0.13
APP:
V1.0.9

[Randy222]

My 703 says:
boot v1.0.14
app v1.1.0

My 703 boots to either Meter volts, or Scope. Whichever side was used last is what it boots to.

It does have the 100ns issue like all the others.
And if I change freq outside of 1kHz the unit won't allow me to even go down to 100ns.

[Randy222]

Did Zoyi advertise the 703 as also a 50Mhz generator.
In the more-apps area there;s the Gen app, but seems I can only get around 325kHz.

There's definitely some odd bugs in my 703. After making some manual changes on scope settings, like signal type from the side port, I simply go back and hit AUTO. With the std 1kHz sq. wave the AUTO appears to step through some time divisions and then settles on one. But sometimes the whole scope part seems to crash / lockup, I then have to power off - on.

[Altair8800]

With the ZT-703S it seems like one of the differences between the older 702S model is that the 702S has a thermocoupler function.  In the newer 703S this function no longer exist but they add in its place a new function called UART in Multimeter Mode.  This is in Multimeter Mode you click the MENU button and it will then display (Language, Auto Off, Bk Light, Uart). 

UART if you switch it to ON is supposed to display Multimeter readings through the COMM port.

Has anybody got this to work, and can you please explain how you were able to do it?

I tried a few times but couldn't get this to work on my Windows computer (it will not recognize or show the Comm port)

[ahakman]

Are you connecting the signal generator output to a usb to serial adapter (or a real serial port)? It's not through the USB port, it's through the signal generator port.

I don't have a TTL USB to Serial adapter here to try it with, but if I measure that port in multimeter mode on AC voltage, I can see a slight increase in AC voltage when I turn the UART function on, and it goes back to zero when I turn UART off.

Yes, it's dumb they didn't do it through a built in usb-serial adapter.

[Altair8800]

Thanks ahakman,

That explains some of the puzzle.

Yes, I was kind of expecting that when you plug the 703S via a USB cable it would show up on the Windows computer with a newly assigned COM port, similar to when you connect and Arduino or ESP32 device.

So I sacrifice an old USB cable and stripped it and connected the 2 USB data wires to the Multimeter Signal Generator Output Port.  Having UART=ON, when I plug into the male end of the USB cable to Windows machine, it does not show as a COM port in Device Manager.  But I did hear Device Manager give a Ding, like it recognized something (I could not easily find the change).

Things didn't work, its late, will try another day...


PS1:  I have visions I might have to use old 9 pin RS-232 cable and hook up to old WinXP computer (that has the old serial ports)...  Or maybe I can use a Serial Port to USB port cable...  Please "Say it isn't so, Joe"

PS2:  In Windows Device Manager if you do not see COM Ports, you might have to click View Menu > Show hidden devices.

[winkot]

Could you take screenshots of the meander with a frequency of 1 MHz and higher?

[winkot]

My batt icon shows the full 4 bars ("full") but power button is still red.

What did batt icon and power button show next?

[wasedadoc]

Thanks ahakman,

That explains some of the puzzle.

Yes, I was kind of expecting that when you plug the 703S via a USB cable it would show up on the Windows computer with a newly assigned COM port, similar to when you connect and Arduino or ESP32 device.

So I sacrifice an old USB cable and stripped it and connected the 2 USB data wires to the Multimeter Signal Generator Output Port.  Having UART=ON, when I plug into the male end of the USB cable to Windows machine, it does not show as a COM port in Device Manager.  But I did hear Device Manager give a Ding, like it recognized something (I could not easily find the change).

Things didn't work, its late, will try another day...


PS1:  I have visions I might have to use old 9 pin RS-232 cable and hook up to old WinXP computer (that has the old serial ports)...  Or maybe I can use a Serial Port to USB port cable...  Please "Say it isn't so, Joe"

PS2:  In Windows Device Manager if you do not see COM Ports, you might have to click View Menu > Show hidden devices.

I do not have a 703 but my understanding is that it will output serial UART data at 3.3 or 5 Volts. That cannot be connected directly to a USB port. It might work if connected to the RxD pin of a PC 9 pin serial port. If the PC has only USB ports you will need a "USB  to TTL" type interface.

[ahakman]

PS1:  I have visions I might have to use old 9 pin RS-232 cable and hook up to old WinXP computer (that has the old serial ports)...  Or maybe I can use a Serial Port to USB port cable...  Please "Say it isn't so, Joe"

Yes, you need to use a TTL RS232 to USB adapter if your computer doesn't have native serial ports. The meter will be outputting raw TTL RS232 - you can't connect that directly to a USB cable - they're not the same protocol at all.
It needs to go.

meter --> ttl rs232 to usb adapter -> usb port on computer

Even if you have native serial ports, you'd probably need a level shifter - I'm guessing the meter is outputting 3.3V signals, and a real serial port is expecting +/- 12V. Maybe some modern serial ports work directly with TTL, but even if so, 3.3V might be too low for reliable communication.

[rsjsouza]

The ZT-702S oscilloscope does not show the end of charging on the display. The battery icon does not change. How to determine that charging has ended?

While charging, the On/Off button of my ZT-702S glows red. When the DMM is fully charged, the button simply powers off. The battery indicator shows as fully charged. 

[winkot]

When the DMM is fully charged

How long does it take to fully charge?

[rsjsouza]

When the DMM is fully charged

How long does it take to fully charge?

Unfortunately I rarely let it go to 0%, thus I don't remember the time for a complete charge.

Today it took about 1/2 hour to charge it from about three bars to full.

[kwass]

Yes, you need to use a TTL RS232 to USB adapter if your computer doesn't have native serial ports. The meter will be outputting raw TTL RS232 - you can't connect that directly to a USB cable - they're not the same protocol at all.
It needs to go.

meter --> ttl rs232 to usb adapter -> usb port on computer

Even if you have native serial ports, you'd probably need a level shifter - I'm guessing the meter is outputting 3.3V signals, and a real serial port is expecting +/- 12V. Maybe some modern serial ports work directly with TTL, but even if so, 3.3V might be too low for reliable communication.

Yes, a TTL RS232 to USB adapter works just fine.  The meter outputs a 3.0 volt signal as you can see from the scope capture.

Here's are some sample output lines,  note that there is no <CR> nor <LF> marking the line ends this is my edit.  The meter sends about 3 lines per second so the delay between records can be used as a break.  Also, the output doesn't specify AC or DC, this seems to be an oversight.  Finally current is called "electricity"!

Code: [Select]

Voltage:-23.211 mV
Voltage:0.0003 V
Resistance:0.L KOM
Resistance:002.15 OM
beep:. OM
beep:000.04 OM
Diode:. V
Diode:00.001 V
Electricity:0.0000 A


[winkot]

What does it mean Coupling?

[Altair8800]

Yes, a TTL RS232 to USB adapter works just fine.  The meter outputs a 3.0 volt signal as you can see from the scope capture.

Here's are some sample output lines,  note that there is no <CR> nor <LF> marking the line ends this is my edit.  The meter sends about 3 lines per second so the delay between records can be used as a break.  Also, the output doesn't specify AC or DC, this seems to be an oversight.  Finally current is called "electricity"!

Katie/KWASS:

Could you please tell what exact Baud settings you used?
Baud Rate:  115200
Data bits: ??[5, 6, 7, or 8]
Parity: ?? [even, odd, none, mark, space]
Stop bits: ??[1, 1.5, or 2]
Flow control: ??[hardware, software, none, Xon / Xoff]
Handshaking: ??[none, XON/XOFF, RTS/CTS, DSR/DTR]
Language:  ??[ASCII, utf-8, other]
Delay:  ??[some serial communication programs have this...]

I know that standard setting is Parity=N, Data bits=8, Stop bit=1, Flow control=None, but not sure with this company Zoyi since no exact documentation. I'm not sure they even used standard settings...

I was able to use a USB to TTL RS232 9-pin adaptor, but in the serial output programs I use the message is always garbled.  So some setting(s) is(are) wrong.

[ahakman]

I don't think I've ever seen a TTL usb to serial adapter have a 9 pin connector on them. Usually they have loose wires (flying leads), or raw solder pads that you solder your own wires to. Having a 9pin connector typically means it's a full RS232 voltage adapter, and NOT TTL.

You're probably getting garbled communications because 3V is not enough to reliably signal the USB to Serial adapter you have because it's not actually a TTL level adapter.

The settings will be 115200, 8, N, 1
No flow control
No handshaking
ASCII
and no delay (character delay is usually only for transmission - it introduces a slight delay between characters - it does nothing for reception)

[kwass]

I don't think I've ever seen a TTL usb to serial adapter have a 9 pin connector on them. Usually they have loose wires (flying leads), or raw solder pads that you solder your own wires to. Having a 9pin connector typically means it's a full RS232 voltage adapter, and NOT TTL.

You're probably getting garbled communications because 3V is not enough to reliably signal the USB to Serial adapter you have because it's not actually a TTL level adapter.

The settings will be 115200, 8, N, 1
No flow control
No handshaking
ASCII
and no delay (character delay is usually only for transmission - it introduces a slight delay between characters - it does nothing for reception)

That's exactly what I used for settings.  For hardware, I used something like this from Amazon.  It only has RX, TX and GND so there's no way to mess up the handshaking options! https://www.amazon.com/DSD-TECH-3-5mm-Cable-Interface/dp/B07XXVF4RM

[naiclub]

I just purchased it last year.

[wasedadoc]

Yes, a TTL RS232 to USB adapter works just fine.  The meter outputs a 3.0 volt signal as you can see from the scope capture.

Here's are some sample output lines,  note that there is no <CR> nor <LF> marking the line ends this is my edit.  The meter sends about 3 lines per second so the delay between records can be used as a break.  Also, the output doesn't specify AC or DC, this seems to be an oversight.  Finally current is called "electricity"!

Katie/KWASS:

Could you please tell what exact Baud settings you used?
Baud Rate:  115200
Data bits: ??[5, 6, 7, or 8]
Parity: ?? [even, odd, none, mark, space]
Stop bits: ??[1, 1.5, or 2]
Flow control: ??[hardware, software, none, Xon / Xoff]
Handshaking: ??[none, XON/XOFF, RTS/CTS, DSR/DTR]
Language:  ??[ASCII, utf-8, other]
Delay:  ??[some serial communication programs have this...]

I know that standard setting is Parity=N, Data bits=8, Stop bit=1, Flow control=None, but not sure with this company Zoyi since no exact documentation. I'm not sure they even used standard settings...

I was able to use a USB to TTL RS232 9-pin adaptor, but in the serial output programs I use the message is always garbled.  So some setting(s) is(are) wrong.

If your adaptor has a 9 pin plug to fit a 9 pin SER socket on a PC, connecting that to the Zoyi will never work.  For "TTL serial" a logical 1 is signalled by positive voltage and a 0 by zero (or close to zero) voltage. But true RS232 is different. A 1 is negative voltage and a 0 by positive voltage. That is why RS232 interface chips '188 and '189 are inverting.

[Randy222]

Too bad it's not a dfu device using STM chipset, the STM driver is a simple USB to virtual COM.

[Randy222]

I don't think I've ever seen a TTL usb to serial adapter have a 9 pin connector on them. Usually they have loose wires (flying leads), or raw solder pads that you solder your own wires to. Having a 9pin connector typically means it's a full RS232 voltage adapter, and NOT TTL.

You're probably getting garbled communications because 3V is not enough to reliably signal the USB to Serial adapter you have because it's not actually a TTL level adapter.

The settings will be 115200, 8, N, 1
No flow control
No handshaking
ASCII
and no delay (character delay is usually only for transmission - it introduces a slight delay between characters - it does nothing for reception)

That's exactly what I used for settings.  For hardware, I used something like this from Amazon.  It only has RX, TX and GND so there's no way to mess up the handshaking options! https://www.amazon.com/DSD-TECH-3-5mm-Cable-Interface/dp/B07XXVF4RM

Did you cut off the 1/8" end and wire it to a USB-C male end? My 703 only has USB-C
Is there a 1/8" female to USB-C adapter made for just the serial lines?

[Veteran68]

Did you cut off the 1/8" end and wire it to a USB-C male end? My 703 only has USB-C
Is there a 1/8" female to USB-C adapter made for just the serial lines?

As noted earlier in this thread, the 703's UART communication occurs over the signal generator output. Not the USB-C port.

[Randy222]

Did you cut off the 1/8" end and wire it to a USB-C male end? My 703 only has USB-C
Is there a 1/8" female to USB-C adapter made for just the serial lines?

As noted earlier in this thread, the 703's UART communication occurs over the signal generator output. Not the USB-C port.

What port / jack is the "generator output" port?
My 703 has one usb-c, and two BNC's at the top.