MC43 Directional Frequency in

Michael Carlyle 7 years ago in IQANdesign updated by Jos Lentfert 3 years ago 13

I get an error when using the directional frequency in as speed/direction on an MC43.

The channel turns red and gives and error as soon as I change the property to Frequency/direction.

If I attach an XA2 to the MC43 and add this channel to that module - it is fine. Is there a reason this input on the MC43 will not accept configuration as Frequency/Direction?

Looks like a bug in IQANdesign. We're investigating.

It is not a bug, a more accurate description would be "lack of feature".

The module that has support for the sensor type "Frequency/Direction" are the XA2 and XC21/22/23.

These modules handle the situation when the on/off direction signal changes, and count the pulses from the frequency signal in the correct direction.

In version 2.x, it used to be possible to set type "Frequency/Direction" on MC2 the DFIN channel, but the MC2 hardware does not have built in support for it, and the old MC2 implementation was one that could relatively easily be built with application logic instead, by combining a FIN and DIN.

It might be possible to add the feature of proper built-in handling of the sensor type "Frequency/Direction" on the MC4 series.

Out of curiosity, what type of sensor are you using? (if that is information that can be shared on the forum)

Most sensors for this purpose that I come accross are of quadrature type, and I only recall ever coming across a sensor with a frequency output and a separate direction output once in applications I have worked on.

Ok, the model with two phase shifted frequency outputs should work with the DFIN channel property sensor type set to Quadrature, so that would work with IQAN-MC4x using existing software versions.

We get an error when reading these sensors.  It seems to read the directional speed fine when set to quadrature but an error message comes up for that input.  When I only use one input as a frequency-in - there is no error.  Is there an additional error check for quadrature vs. directional frequency in?

The DFIN channels (quadrature) on IQAN-MC4x modules are comparing the frequencies of the two input pins. There was a problem with this error detection being too sensitive, this is fixed in 4.07.14 (and will be fixed in 5.01)



I tested the directional frequency with the Rexroth DSA speed sensors and the errors are gone with Iqandesign 4.07.14.

As a feature request - could we turn off the error check for the DFIN as we are getting errors running the signals through a rotary manifold and we seem to lose contact intermittently and it creates nag messages that we cannot block (other than to disable the sensors).

We are looking at making a de-glitching function for MC4 frequency inputs. If there is a glitch that looks like a too high frequency (and the DFIN diff check registers this), a de-glitching function would help. 

If the problem is that one signal drops out for a bit longer, it probably wouldn't help. 

Hello Michael, just a tip by experience, Lot of problems can be solved when running signals specially the frequency and CAN signals over rotary joint in the machine to have good quality rotary joint capable and specially designed for transferring low voltage & low apm. (mA) signals and CAN bus data.