Hi,

I am using the Logo! soft comfort software and i was wondering if there is a block which will enable me to convert a pulse signal coming from an encoder and convert this to an analogue signal of 0 to 10v. 

I basically need an encoder to communicate with a VFD so that the speed of a motor can be determined by the encoder which is attached else where on the machine (not on the motor).

Any help would be great. I apologize as I am new to PLC's so this may not make too much sense. 

Thanks!

Hi, thanks for your reply.

I am not certain, but I think a train of 50 pulse signals come from the optical encoder every revolution which isn't particularly a high frequency signal as the wheel which rotates has a circumference of 0.5m and the cable runs through the encoder wheel at a speed where the maximum frequency of the pulses will only ever reach around 100Hz.

I would need to somehow convert the pulses measured to a voltage signal between 0 to 10v within a PLC program so that say for example the encoder is measuring a line speed of half of the maximum, then a 5v signal will be converted which I could compare to a voltage given by a speed pot and send a signal to the VFD to increase the speed until the desired voltage is reached (being the voltage set by the pot).

I understand there are signal converters out there which can be used for this application but I was wondering if the Logo PLC has any capability of doing such a thing?

Thanks.

Ok I understand now,

Thank you for your help!

JoelShawsy99

Hi,

I am using the Logo! soft comfort software and i was wondering if there is a block which will enable me to convert a pulse signal coming from an encoder and convert this to an analogue signal of 0 to 10v. 

I basically need an encoder to communicate with a VFD so that the speed of a motor can be determined by the encoder which is attached else where on the machine (not on the motor).

Any help would be great. I apologize as I am new to PLC's so this may not make too much sense. 

Thanks!

 There are interface board sell on Aliexpress. It convert frequency to analog volt output. It can working alone and can be adjust the gain of output to suit your purpose.