Input Events

[jonfarrugia]

I am working on a project in which I need to monitor a sensor, on a powerflex 755 controlled conveyor, at a relatively high rate of speed. Once the sensor is triggered, I will need to turn on an output once the conveyor travels a specific distance. Currently the input is wired to a 1734-IB8 and the Output is wired to a 1734-OB8, both connected to the same 1734-AENT.

I can wire the inputs to the Powerflex 755 registration inputs, but I don't believe this drive is capable of providing registration. Although I may be wrong.

I tried to trigger an event on the module change of state but these modules don't seem to support that feature.

The only other option I can think of is to wire the Input and Output directly to an input/output module on the processor.

Any insight would be appreciated!

 

[jonfarrugia]

Just got off the phone with tech support.

The drive does have registration input just as long as you use the PF750 Universal Feedback Module (20-750-UFB). Thankfully we are using that module!

Now the next question I have is about the registration event.

Does the event get triggered on a change of state? positive-edge and negative edge?

 

[jonfarrugia]

Think I figured out my own question. From my understanding, I need to use the MAR instruction to register the event conditions. Once the conditions are met the even is triggered.

I've run into another snag.

My conveyor has two sensors I need to monitor. They will be connected to the Powerflex 755 drive into registration input 1 and input 2. These could almost trigger at the same time.

The machine uses these sensors to activate a glue nozzle a small distance from the sensor. As the product passes the sensor. The registration input logs the actual position and triggers the event. In the event logic I have a MAW instruction which takes the registered position and adds an operator adjustable glue start position. Once that position was reached, The motion watch event would be triggered to turn the glue nozzle on.
The problem is that I need to watch for two positions on the same conveyor, yet there is only one watch position event.

Any idea how to create two watch events on the same axis?

 

[MichaelG]

Any idea how to create two watch events on the same axis?

3 Ways - bet that there are more

1. make up your own MAW - simple maths
2. Add a Virtual Axis that is always geared 1:1 to your PF 755 Axis then do the MAW on that axis as well.
3. Learn how the MAOC function operates and use that to fire the outputs when the MAR events occur
   Bonus with MAOC
   • Speed compensation is built in
   • if the PF 755 stops when the glue is to be fired you can add timers to automatically turn off after a short time