PWM Fan (Four Wire Fan)

[nomonick77]

Hi, does anyone have a program for a 4 wire fan? I have a BX-DM1E-36ER3-D, and I want to be able to control the speed of the fan. Here's a link to the website I was using to try and understand Pulse Width Modulation with Ladder Logic, "https://www.sanfoundry.com/plc-program-perform-pulse-width-modulation/".

I would appreciate it if you had instructions for how you control the fan speed. It could be with push buttons, a potentiometer, or even just changing the value in the program. I'm not very familiar with Do-more designer but I've done some PLC programming with an Allen Bradley before.

Thanks,
Nomonick77

[RBPLC]

What type of fan are you trying to control and what's your application? Some controllers have onboard PWM high speed outputs and there's an instruction that makes this type of control simple. The problem is, you have a relay model which is not appropriate for PWM.

[nomonick77]

It's hard to find a link to the exact fan, but it's a DC12V, 1.41A, 4-wire fan. Brand: Jeek, Model: AGE12038-12U.

As for the application, I'm more or less doing this for practice but I would love to be able to control it using something like the dial of a potentiometer or using a thermistor. The only two PLCs I have that I can experiment with are the BX-DM1E-M-D and this BX-DM1E-36ER3-D.

I believe I read in the manual that this one is capable of PWM, so if there's a way to use it for this I would love to try it out.

[RBPLC]

They're both capable of PWM, it's just that your specific 36 point model has relay outputs which are not suitable for PWM. You could buy a high speed module to perform PWM.

[nomonick77]

Do you have a recommendation for a specific BRX PLC model? I'm not sure if I'll be able to purchase a new PLC currently since this isn't for an official project, but if the price isn't too bad I'll definitely consider it.

[franji1]

One of the HSIO expansion modules is all you need, not an actual PLC.  You can attach the HSIO expansion module to either of your BRX PLCs that you already have.

As to which one, I don't know (I'm a software guy).

[SceneryDriver]

Hi, does anyone have a program for a 4 wire fan? I have a BX-DM1E-36ER3-D, and I want to be able to control the speed of the fan. Here's a link to the website I was using to try and understand Pulse Width Modulation with Ladder Logic, "https://www.sanfoundry.com/plc-program-perform-pulse-width-modulation/".

I would appreciate it if you had instructions for how you control the fan speed. It could be with push buttons, a potentiometer, or even just changing the value in the program. I'm not very familiar with Do-more designer but I've done some PLC programming with an Allen Bradley before.

Thanks,
Nomonick77

Example program attached.  I've successfully used this code with multiple Noctua fans, but others should work as well. 

Note that you will need to use a sinking HSIO PLC output.  A sourcing output will not work, and will damage the fan's PWM input.  PWM capable fans have an internal pullup resistor that allows the sinking output to work as long as the duty cycle of the PWM is inverted (the code does that). 

Note that the fan's 0V and the PLC output's common must be connected together.

PLC's HSIO output needs to be set to PWM.


SceneryDriver