Tonghui TH2830 LRC meter serial port, HOW ? BRAKE THRU, ALIVE

[oz2cpu]

did any one figure out how to connect a PC to its serial port ?

nothing seems to work
please tell me how you did it ?

[Martin72]

Hi,

We got the ST2830 from Sourcetronic, which seems to be 1:1 the same.

https://www.sourcetronic.com/shop/de/kompaktes-lcr-meter-st2830.html

You can download usb driver, but the software isn´t for free.
Maybe it will work with the one from member HKJ.
Nevertheless, I could call the german support and ask them for the RS232 interface(not mentioned in the manual), would post the answer here.

Martin

[oz2cpu]

I am only interested in the serial port, since my PC is too far away from the instrument for USB connections.
a serial cable can easily be 10meters, but usb can not.

RS232C in a DB9 connector should be a very simple industrial standard,
some variations exist, so for clarify it could have been nice to see the pinout and handshake requirements explained in the user manual,

i dont get any answers on *IDN?  i am in 8n1 9600 baud and scpi mode
i also tried the talk only mode, and still dont see any kind of data out,
double checked with a scope.

any kinds of help you maybe able to come up with, is much appreciated,

[coromonadalix]

Usb can  if you have an usb cable repeater or extender,  some have 15 feet in length ... or you can use usb to fiber converters an can go to higher distances ...

[oz2cpu]

using usb, is not going to solve my question ; how to make serial port work

[2N3055]

Apart from usual DTE/DCE confusion (straight or null modem cable) if it uses hardware handshake there is a good chance it uses classic RTS/CTS system.. Also, maybe there is an option in config to disable hardware handshake...

[oz2cpu]

thanks 3055 i tried all possible combinations of handshaking
as explained in several web documents about rs232 9pin connector

i see no info in the manual about handshaking
i see no way to turn it on or off in the settings

anyone with a similar unit ?
please see if you can get it to reply to *idn?
or say anything in talk only mode ?

maybe just use a scope, and what signals need to be correct for it to say anything at all ?

this was supposed to be a 10 min challenge (normally this stuff is that darn simple)

[2N3055]

thanks 3055 i tried all possible combinations of handshaking
as explained in several web documents about rs232 9pin connector

i see no info in the manual about handshaking
i see no way to turn it on or off in the settings

anyone with a similar unit ?
please see if you can get it to reply to *idn?
or say anything in talk only mode ?

maybe just use a scope, and what signals need to be correct for it to say anything at all ?

this was supposed to be a 10 min challenge (normally this stuff is that darn simple)

Scope time, seems to me....

[oz2cpu]

YES IT IS SCOPE TIME :-)
but so far.. no sign of life on any pins,
feel so much like a looser for not beeing able to solve this lo-mo-challenge.. yet

[voltsandjolts]

Any activity as the unit powers up?

Since they are charging for software, worst case would be a secret unlock code sent to the device before it will talk to you.

[oz2cpu]

great idea.. i rebooted many times, not a glitch that could look like a serial byte seen..

but i got a few ideas now, i will try to switch it into usb mode, and then back to serial, maybe it is stuck in odd configured state some how

[Martin72]

Nevertheless, I could call the german support and ask them for the RS232 interface(not mentioned in the manual), would post the answer here.

I got an answer today.
Well...It won´t help a lot, but I tell it here.
The RS232 interface you can reach with the software ST4 and you can run SCPI commands via it.
Then they tell me to use a datacable with crossed connections (RX,TX) and obey the baudrate (9600 or 19200).
That was it from them, I can do some tests when we got our LCR back from calibration in the next week.
Martin

[oz2cpu]

thanks a lot,
I only tried 9600 8n1 scpi mode
i crossed the signals,
verified with scope the tx signal is not connected to the other side tx, of course.

no reply on *idn?
and nothing come out in talk only mode

I also tried to wire all handshake signals as explained in the rs232c documentations found online
2-3 rx-tx
3-2 tx-rx
5-5 gnd
    on the TH2830 side i tried 4 to 6 and 7 to 8
    and also 1-4-6 , 7-8 connected together as suggested by many sites

still no luck, so i feel we need some one else to please try too, please folks ?
I had the idea so many people had this unit ? or the ST2830

[Martin72]

In the answer, they told me also something I don´t understand:

Pay attention to CR and LF when transmitting and receiving.

 

Our ST2830 should arrive next tuesday/wednesday.

[oz2cpu]

>Pay attention to CR and LF when transmitting and receiving.

dont we just love help like that ??

[oz2cpu]

little video to explain where we are:

https://youtu.be/pi1_lMlIY_Q

as far as i tell by this experiment

only pin 2 and 3 are used in the serial connector..
so no hardware handshaking is used at all

[oz2cpu]

BRAKE THRU

https://youtu.be/D_BnIYA0njY

end of line must be 10 (also called LF)
use Tera Term to see it is working
NO HARDWARE HANDSHAKE USED.
talk only, dont work,
so far no luck figuring out how to read measurement values,
manual is very hard to understand.. will update if/when we solve that.

[Martin72]

(also called LF

Aha...

[oz2cpu]

QUESTION : 
can you show an example, how to read the measurement values of capacity and impedance?
or whatever the mode of measurement that is selected..

I do not understand: 
the page command
the display command
the line command
the display:line command

none of it seems to work, all i get is a beep,
 
need examples in the manual that works..
also the listed page examples listed is not what the instrument reports

it seems like i need to select a screen page, and on that page, select the correct line,
and then read out that line, no luck..


what i have working :
the frequency command works

frequency?
reports the current frequency

frequency 100
sets the frequency to 100hz
and so on..

[Martin72]

Tomorrow our ST2830 should arrive ( after over 5 weeks...) at last.
If I get the time I could try something on it.
How did you transfer the commands to your lcr, via the commandline from HKJs Testcontroller software?

[oz2cpu]

Hi martin

I used TERA TERM
with the settings and wirings explained in the last video

i look so much forward to hear if you are smarter than me :-)
please figure out how to read measurement data

so we can make a cool curve tracer with Test Controller..

[Martin72]

Well, let´s see...
When I don´t get the chance at work, I´ll "loan" the meter for a weekend (can´t promise the forthcoming weekend) at home. 
Not exactly the same, but I have more or less the same problems with my ET4410, you can do some things on the commandline, but the script won´t work as expected.

Martin

[oz2cpu]

i think we need to start from the bottom,
understand the command line, document it, share all our findings,
then we have a place to direct other users, and our skilled script helpers,
if we all have a deep understanding of how the commands are truely working towards the instrument,
we have a fair chance creating a cool program / driver

[oz2cpu]

>from the manual

>7.1.1 DISPlay subsystem commands
>MEASlay subsystem commands are mainly used to set the display page for the instrument.
>The :DISPlay? Query returns the current page.

DISPlay?
RETURNS ERROR BEEP

display:page?
returns
< MEAS DISPLAY - 1 >

wich is NOT one of the listed posibilities ?? see page 72 manual

DISPlay:PAGE MEASurement

DISP:LINE "Resistor meas"
DISPlay:LINE?
returns
Resistor meas

DISPlay:RFONt?
returns
LARGE

DISPlay:RFONt TINY
set the result size to tiny (but dont change measurement time)

so some of that seems to work


>7.1.2 FREQuency subsystem commands

all the listed examples here, seems to work. as explained erlier

i am still not able to read a single type of measurement
china support really try to help,
when i ask a and ask b, they answer c and d
so i have not learned anything usefull from them yet.

anyone else with more luck ??


BY THE WAY : the instrument dont contain a bullet prof incomming values / range / command handler,
with timeout and all that.
so there are a few ways to freeze it..
play a bit with disp:line and parameters to figure out how to read data via their examples, and you get frozen unit.

power off/on restore normal opperation.

[Martin72]

I´ve asked the sourcetronic support, if there is a demo version of their ST4 software avaible, just to play around.
No, only full for nearly 300 bucks..
Nevertheless, our ST2830 is back again, at last.
When I get the chance at work I´ll do some tests, otherwise take it to home like mentioned it before.