Author Topic: Serial to usb on Kunkin KP184 electronic load  (Read 46782 times)

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Offline interflexo

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #75 on: February 09, 2021, 12:52:21 pm »
New KP184 Software Version 1.0.13.0:

Changes:

1. Replaced several functions from external lib modules that will be deprecated in the future.

Setup KP184 Software V1.0.64.0
« Last Edit: February 14, 2024, 08:31:31 pm by interflexo »
 
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Offline Dwaine

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #76 on: February 10, 2021, 03:41:10 am »
I love my Kunkin KP184 electronic load and would like to control it via the serial port (or RS485, don't care which), but none of the adapters I've tried (FTDI, Prolific, all the usual suspects) work.

I'm still looking to find the equipment that doesn't work with this adapter:



I use one since 2005 (this is my second one since I lost my previous one, that were only Keyspan in the brand): From using with a Renishaw QC10 Ballbar System to Rollover Cisco Cables, from NSN MGW/MSS terminal connection to old measurement equipment, it never let me down, including Allen-Bradley/Siemens Simatic PLCs. It's based on the TI 75LV4737A Multichannel RS232 Line Driver/Receiver, so it have have HW handshake.

It's a little expensive compared with other models, but is probably the only one you will need for the rest of your professional life.

Those keyspan usb serials will work with any device you throw at it.   I paid $89.00 about 10 years ago.    I have a few Kenwood radios that only work with the Keyspan USB cable.

 

Offline interflexo

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #77 on: February 17, 2021, 02:24:15 pm »
New KP184 Software Version 1.0.14.0:

Changes:

1. Fixed issue related to configuration dialog file browse select controls startup folder.

Setup KP184 Software V1.0.64.0
« Last Edit: February 14, 2024, 08:31:48 pm by interflexo »
 

Offline snoozer

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #78 on: February 20, 2021, 01:03:34 pm »
Hello,

I just thought I check in here because my recent purchase KP184 does also not work with the GUI software or the CLI software which was links further up in this topic. I have done a bit more digging to check if I possibly have an issue on the circuit side of things. I have used a scope to probe the signal presented on the MC side of the RS232/485 Isolator device U23 with the number 1201ARZ. By setting the KP184 to host mode I can make it send "stuff" as if it was controlling the slaves. I can see a signal with nice sharp edges there. Characters also show up on an attached serial terminal. I have also tested the other way around, sending "J" characters from the serial terminal on the PC to the KP184 and I can also clearly make out the "J" send on the MC side of the Isolator U23. I was not able to probe on the MC itself with the scope, the pitch is a bit to small for the probes but I did check continuity and that's fine. From the observations I would have to conclude there is an issue in the MC not doing anything when commanded to by means of serial communication. It would look to me as if the firmware just does not do what it should. Has anybody found a solution to this or is there maybe a firmware that works with my hardware that can be programmed into the KP184

Board Version 4, the top line on turn on has a couple of chars and 184 after. Assume its a version number, maybe 1.84 ?

Kind Regards
Jan Paulini

PS: I have tested with the scope at 2400 baud as well as 115200 baud. There was no issues with either.

PPS: Just for completeness, I have checked with 3 different USB/RS232 interfaces. Also tested with 2 different RS485 interfaces on the A and B terminals of the terminal block in the back of the KP184. No success.
« Last Edit: February 20, 2021, 01:25:26 pm by snoozer »
 

Offline interflexo

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #79 on: February 21, 2021, 11:36:38 pm »
This is most unfortunate. It looks like a firmware issue to me. Thanks for the comprehensive tests.

Does anyone have a KP184 PCB Rev.04 with a working RS232 serial interface?

I remember someone mentioning there is more than one PCB Rev.04 layout and a PCB Rev.05 here.

I browsed Kunkin website. At the low end they have now the KP283 / KP284 (2CH independent 15A/20A 80V). They dropped the PC RS232 interface but maintained the RS485 (host/slave) interface.
« Last Edit: February 21, 2021, 11:42:10 pm by interflexo »
 

Offline snoozer

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #80 on: February 22, 2021, 06:33:53 pm »
Hello again,

in the meanwhile I had a PM regarding this issue from another forum member. He made a very valid observation, the 184 in the 1st line at boot up with the two characters before is obviously the model number KP184, that did not click with me ;-) The 2nd line shows 2020 and the 3rd the address 1. For clarification I add a picture of it below the post. I also have a picture of the board version added for convenience. It appears to be Version 4 202007. So I am definitely not the only one with the issue, there appear to be at least 2 other forum members with the same issue according to the PM I got. I am not going to quote a PM here, I leave that to the person that send me the message if he things it is of any help to the issue.

I hope we can get to the bottom of the issue and fix it in the end. It's not the end of the world for me, I appear to be lucky enough to have an otherwise working instrument which does not seem to be the case for some people. The serial communication would still be a nice extra to have.

Thank you !
Jan P.

PS: Hi @interflexo, thanks for the hint re the Version 5 PCB. I got my unit only a week ago but may have been in stock for some time at Banggood ES warehouse where I got mine from (EU citizen). The KP283/284 looks way different of the control side of things, a lot simpler I guess. Not sure if any parallels could be drawn there apart from maybe the high power side of the instrument.
« Last Edit: February 22, 2021, 06:49:20 pm by snoozer »
 

Offline Treed

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #81 on: February 26, 2021, 04:29:34 am »
I independently got to the same conclusion. I tried sending commands to the load and probed the signal all the way to the MCU but just couldn't get a reply. When it's in host mode it sends commands when pressing buttons and in slave mode it reacts when repeating those commands back to it. It doesn't reply with anything though. I have a Ver04 20191111.
It seems Kunkin just broke the firmware on all Rev4s :(
 

Offline snoozer

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #82 on: February 27, 2021, 08:46:13 am »
Hi,

I just had another closer look to be sure. The USART1 TX and RX are on PB6 and PB7, thats pin 42 and 43 on the LQFP48 package of the MCU STM32F030C8. Both pins correctly connect to the Dual-Channel Digital Isolator U23. Do other board versions have the same MCU ? I have a couple of pictures attached below. Not the best quality, sorry.

Kind Regards
Jan P.
 

Offline aristarchus

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #83 on: February 27, 2021, 02:35:22 pm »
I independently got to the same conclusion. I tried sending commands to the load and probed the signal all the way to the MCU but just couldn't get a reply. When it's in host mode it sends commands when pressing buttons and in slave mode it reacts when repeating those commands back to it. It doesn't reply with anything though. I have a Ver04 20191111.
It seems Kunkin just broke the firmware on all Rev4s :(


The KP184 that got here since July. 2020, is working ok regarding RS232 and RS485.

Upon power on, it shows this on its display:
KP184
2001
Ad.001

And internally it has this main board version
VER:04
20191111

So, not all v4's got this problem as this one works ok.

See also some previous posts with relevant info for RS232 and RS485 hardware and connections here
https://www.eevblog.com/forum/testgear/serial-to-usb-on-kunkin-kp184-electronic-load/msg3123158/#msg3123158
https://www.eevblog.com/forum/testgear/serial-to-usb-on-kunkin-kp184-electronic-load/msg3130266/#msg3130266


/PS
Just did a read on other posts that have the comms problem, it looks to me that the issue is there with those that have 2020 shown on the initial  boot of KP184 display, so most likely a newer firmware version problem.
« Last Edit: February 27, 2021, 02:44:48 pm by aristarchus »
 

Offline snoozer

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #84 on: February 27, 2021, 05:17:46 pm »
@Treed, could you check what your boot up display looks like ? Do you have 2020 in the 2nd line as well or something different ?

Regards
Jan P.
 

Offline snoozer

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #85 on: March 01, 2021, 10:30:53 am »
Hi, I am attempting to get in touch with Kunkin now, I have little expectation but hey, cost nothing to send an email.

Rgrds
Jan P.
 

Offline aristarchus

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #86 on: March 01, 2021, 11:18:57 am »
Hi, I am attempting to get in touch with Kunkin now, I have little expectation but hey, cost nothing to send an email.

Rgrds
Jan P.


In attempts to get in touch with them last year received no reply whatsoever, tried almost every possible email and even the chat feature, none worked no reply ever given.

The only way that I managed to get something from them
(the document with the protocol and commands that I published in post  https://www.eevblog.com/forum/testgear/serial-to-usb-on-kunkin-kp184-electronic-load/msg3147906/#msg3147906 )
was via the seller from which I bought the device in ebay, I think your best bet is to use your seller in order to retrieve any response from the company, only the seller I guess knows how to deal with them..

« Last Edit: March 01, 2021, 11:21:16 am by aristarchus »
 

Offline snoozer

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #87 on: March 01, 2021, 12:09:28 pm »
Good point @aristarchus, I have contacted Banggood as well.

Thx
Jan P.
 

Offline interflexo

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #88 on: March 02, 2021, 09:26:32 am »
New KP184 Software Version 1.0.15.0:

Changes:

1. Also accepts Modded KP182 (U23 > ADUM1201 + 2 RX/TX resistors + USB/Serial Converter)

Setup KP184 Software V1.0.64.0
« Last Edit: February 14, 2024, 08:32:13 pm by interflexo »
 

Offline RhdZ

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #89 on: March 03, 2021, 07:57:17 am »
Hello,
I had the same problem with the KP184, that it does not react to commands via RS232 serial interface.
My device shows also 2020 at startup.

I think, I've found the solution to the problem:
The documentation about the serial commands in the manual is wrong!
The checksum has to be sent LSByte first (not MSByte first as written in the manual and shown in the examples).
So for example the sequence for 'Set up load switch' is 01 06 01 0E 00 01 04 00 00 00 01 5F CA
This is according to the description of the Modbus Standard which I found here https://modbus.org/docs/Modbus_over_serial_line_V1_02.pdf
Obviously the older KP184 devices have a failure in Modbus implementation and the manual description is for these older devices  :-\

BR
Reinhard
 
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Offline HKJ

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #90 on: March 03, 2021, 08:05:18 am »
Hello,
I had the same problem with the KP184, that it does not react to commands via RS232 serial interface.
My device shows also 2020 at startup.

I think, I've found the solution to the problem:
The documentation about the serial commands in the manual is wrong!
The checksum has to be sent LSByte first (not MSByte first as written in the manual and shown in the examples).
So for example the sequence for 'Set up load switch' is 01 06 01 0E 00 01 04 00 00 00 01 5F CA
This is according to the description of the Modbus Standard which I found here https://modbus.org/docs/Modbus_over_serial_line_V1_02.pdf
Obviously the older KP184 devices have a failure in Modbus implementation and the manual description is for these older devices  :-\

If that is the case, you can easily test with TestController: https://www.eevblog.com/forum/testgear/program-that-can-log-from-many-multimeters/
Simple change the line "#subDriver Kunkin"  to "#subDriver RTU" in the "Kunkin KP184.txt" file
 

Offline RhdZ

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #91 on: March 03, 2021, 08:25:09 am »
I've already checked that with a terminal program and it works with Checksum LSByte first!
 

Offline HKJ

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #92 on: March 03, 2021, 08:34:43 am »
I've already checked that with a terminal program and it works with Checksum LSByte first!

With TC you can also check if the ID byte is the same and the standard control are unchanged, that is a lot of work from a terminal.
 

Offline RhdZ

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #93 on: March 03, 2021, 08:37:14 am »
OK, I will check with your SW ...
 

Offline RhdZ

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #94 on: March 03, 2021, 09:54:11 am »
The TestController SW does not connect to the KP184.
I've made the change in the Kunkin.txt file and set the com Port (com1) but after 'Reconnect' button there is no connection.

With Terminal SW HTerm it's no problem.

 

Offline RhdZ

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #95 on: March 03, 2021, 09:55:30 am »
HTerm screenshot attached
 

Offline HKJ

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #96 on: March 03, 2021, 10:08:41 am »
The TestController SW does not connect to the KP184.
I've made the change in the Kunkin.txt file and set the com Port (com1) but after 'Reconnect' button there is no connection.

Try start TC with the testControllerDebug.bat file, then it will show what is going on.
 

Offline RhdZ

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #97 on: March 03, 2021, 10:24:56 am »
See screenshot attached.

If I send the command 01 03 00 01 00 02 95 CB via HTerm, the KP184 does not respond.
 

Offline RhdZ

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #98 on: March 03, 2021, 10:48:48 am »
Somewhere I've found another version request command: 01 03 00 01 00 04 15 C9
This works.
Response is: 01 03 04 00 00 07 30 F8 17
 

Offline HKJ

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Re: Serial to usb on Kunkin KP184 electronic load
« Reply #99 on: March 03, 2021, 10:57:09 am »
If I send the command 01 03 00 01 00 02 95 CB via HTerm, the KP184 does not respond.

This means Kunkin do not use the standard modbus protocol, I have added another Kunkin protocol that only swap checksum bytes compare to the old Kunkin protocol.
To test it:
Download: http://lygte-info.dk/pic/Projects/TestController/TestController.jar
Use it to replace the current .jar file
Modify "Kunkin KP184.txt" to "#subDriver Kunkinx", everything else must be the same.
Start testcontroller, initial message must be: 01 03 00 01 00 04 C9 15
Note: It may take some time before the download will download the modified version, it is V1.57 in the About dialog.
 


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