FX3U clone problem uploading a code with gx works2

[eagl1]

I doubt that Openplc has the dedicated functions for the analogue channels

not sure how they interact with the real I/O either

It's described in this page, supporting several microcontrollers:
2.4 Physical Addressing – Autonomy

The FX3U has STM32F103 chip, so I think it should work with the STM32F103CB (Blue pill).

 

[eagl1]

I tried OpenPlc, it's ok but compiling takes a long time, not very good on documentation so although it seems to work I would not use it, probably take me twice as long to produce a section of code compared to the original IDE.

To me at this point I have to use it because it's free IDE.

 

[parky]

Well it's worth a try but if it trashes your plc then I suppose the cost of these clones is not a major concern as stated before once downloaded there is no way back, I suggest you read some posts on the openplc forum here is just one

FX3U Clone and alternative software (firmware)

I would like to know if I will flash this plc with alternative firmware, can I go back with original firmware ? If I will download plc program from beremiz, Can I upload this program later like in Tia Portal on Siemens ?

openplc.discussion.community

 

[eagl1]

Yep, you're right it worth the try, and it should work eventually.

This blog has explained how to hack this board:
Repurposing a PLC Clone for Use with Arduino | HackerNoon

In the blog, he mentioned this:

Once the bootloader was running, STM32CubeProg was launched and communication with the microcontroller was verified. The chip was in read protect mode, so no way to backup the firmware to reverse the board to its original state. All FLASH memory has been erased.

So when I flash this board with anything, I can set BOOT0 and program it with either Arduino IDE or OpenPLC, these IDEs should be the best routes for me.

Programming the board with Arduino C/C++ would be the best route for me, but also I would like to program it with OpenPLC just for project showroom demonstration.

 

[parky]

OK but if you look at the forum from what I have seen there is no support for analogues & probably no support for some other functions unless someone has posted some code. you might as well but an Arduino. Apparently it only supports 14 I/O points but as even if the board has more or less the system should still operate as non exiosting I/O I believe can still be programmed & used as internal bits.

 

[eagl1]

Here in this thread; he mentioned that it support analogous functions:
Analog input and output samples

But he didn't mention the support of output analog function and I didn't find a YouTube tutorial about this function.
But I believe I should get it to work in OpenPLC, and if not then I can program it with Arduino C/C++ and forget about ladder programming.

Now I'm in vacation and I don't have the PLC with me right now, but as soon as I get back, I will start working with OpenPLC I don't think that there would be a huge risk since I can flash it again to program it with Arduino IDE.

Apparently it only supports 14 I/O points but as even if the board has more or less the system should still operate as non exiosting I/O I believe can still be programmed & used as internal bits.

Yep, I noticed that. To the model I have, the pin support is according as it should be. But if another model with more count then that has to be supported in the core source code, and since it's an open source platform, then there will be future contributions to cover this improvement.

 

[eagl1]

Found this about PWM:

 

[parky]

PWM is no good for the board you have as it is relay output, the relays are not fast enough you need transistor output to do PWM, in the FX firmware the PWM instruction only works on a unit with transistor output, however, changing the firmware the PWM would work on an internal bit but that is not much use, on an FX the PWM (Called PLSY) has 3 variables Number of pulses & frequency & the output coil it has to be an actual output, however there is the PLSR (I think) that is used for motion control with dedicated cards.

 

[eagl1]

Yep, with this board having relays I'm not interested in PWM and I don't need it, since I bought that Vdc to PWM converter board which will work on DA0 and DA1 pins on the FX3U which provide 0-10V resolution, so I can use these pins, and I believe OpenPLC should support the DAC functionality, if not then plan B is to do it in Arduino IDE.



I have the one on the left, I tested it and it worked. If the load won't accept PWM signal then I have to search for transistor driver circuit; like this one:


Or design one from the warehouse stock to this simple circuit:



I'm happy now that I know how to move from gx works2 to another platform.

 

[parky]

The only thing to be aware of is many of those PWM amplifiers do not meet the power requirements stated, read loads of reviews on Amazon & many do not come close to the supposed rated power, even some posts on there saying they have recieved units with no pins or connectors. But I have done my own using a chip you can by, it has the capabilities of reverse not many components just the IC & power FET stages(4) to swap the direction

 

[eagl1]

Sounds interesting, please provide me with the schematic or circuit idea draft.

 

[parky]

Unfortunately I don't have it anymore, It was on my PC at work & the company went into liquidation so I was unable to access anything.
I believe it used an IC called TC4469 or something like that,
Here is a circuit I found using that IC it certaily looks very similar

tc4469 - Bing

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[eagl1]

Yep, that's the h-bridge circuit. There are many dc motor drivers some uses h-bridge driver ic; like, L298N board.

OK, I got it now, I just have to search for a motor driver that accept both variable/pwm input voltage. I already have the L298N board, I just have to test it with the FX3U controller.

After testing I might purchase one of these boards:



I would desolder the potentiometer, and connect the DAC pins, assuring that the input side can handle 0-10V.