Three-phase motor control with rs 485

Hello,

I want to control three phase motor driver using Arduino mega and rs485 ttl. There are buttons on the motor driver and there are some menus. For example, if I set 1 in p09 setting in the p0 menu to reverse the motor, the motor starts to turn in one direction, and if I make 0 where it is 1, it starts to turn in the other direction. I want to control this with arduino. can i do this? How can I do it?

Motor Driver: GAIN 0.75kW~3.7kW – GMT Industrial Automation Solutions

RS485: RS485 to TTL Module – Art of Circuits

Thanks.

Your link has this:"RS-485 communication port supporting Modbus RTU". Did you research that protocol in relation to an Arduino?

Yes, as explained in Chapter 8 of the motor driver user manual "MODBUS Communication Protocol".

I did not research exactly as you said. To control motor driver using Arduino rs485. I searched this way but couldn't come to a conclusion.

But did you find examples of using Modbus RTU?

There are also videos I've seen of doing it. But I did not understand anything, I could not see a well-understood explanation

Can't help with that. Perhaps repetition will make a difference/

What are you wanting to achieve? If you just want a box that allows you to start and stop the motor and control its speed from some buttons and maybe a knob then you dont need an Arduino. Or would the Arduino be performing some other functions?

For example, at the 20th second of the code I will start the engine and turn it one direction, then at the 40th second of the code I will turn it in the opposite direction and when the code is finished I will stop the engine..

OK. Well all these variable frequency drives ("VFDs") have options either for serial control using modbus or by using switches for start, stop, e-stop, direction, and a dc voltage or current for speed. You could control your VFD by getting the Arduino to generate the correct logic signals for start/stop etc and a voltage for speed control. Depending on your programming experience this might be an easier approach as you wouldn't have to learn modbus, use a library, and all that stuff.

On the other hand, there isn't much information on the characteristics of the control input terminals, it just says "PNP or NPN" with nothing on logic levels; and you would have to adapt the 0-5 volt output voltage range of the Arduino to 0 - 10 volts for the VFD which would need an amplifier. So again, depending on your hardware knowledge and experience , this could be equally hard for you.

Are you actually driving a machine with this motor? If you just want to experiment with motor driving I think you could be much better off starting with a low voltage DC motor rather than a 3 phase induction motor and VFD. Safer too!

I have a huge machine in my hand and it is managed by plc, or rather it cannot be managed. Those who built the machine before have set a password and we cannot access the plc code. so we will check it with arduino. I already have this motor driver and I want to use it.

OK, understood. Sorry I can't help with modbus/rs485.

can someone help me?

After 2 minutes on Google I suggest you forget Arduino and just use a PC. There seem to be several modbus scripting apps around.

Are you sure that controller can actually reverse the motor ? Can the motor run in either direction( internal cooling fan) ?

The duty cycle you want may need a motor and controller suitable for that ( as there is a lot of stop start , braking and reversing .

See post 12.

I don't want to use a computer. I can already control the motor as I want with the motor driver. what I want is to be able to turn the engine right, left, stop, start according to my editing. I want to control it with Arduino.

Yes, I'm sure the motor driver can do that. I tried and it worked. It is already managed by a plc. But since I have different things in mind, I want to separate it from plc and manage it with arduino. You can see the specifications of the driver in the 1st message.

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