Powerflex 400 Amps displayed on my HMI?

Hello,


(Simplified explanation)I have a Powerflex 400 running a fan/vacum system that sometimes gets overloaded and clogged. What is happening right now is a maintenance guy is standing at the panel watching the amps on the display in the event a clog occurs. If he sees the amps run high, he knows the vacum tube is beginning to clog and removes the tube from the product bin. What I want to do is automate the proccess... I need to get the amps from the PF400 and into my processor (CompactLogix L35E). I would also like to display the amps on my HMI (Panelview Plus) so they can close the door and stay out of the panel!!

BTW: I have the PF400 connected to the logix controller with a 22-comm-e but all I'm doing right now is checking to see if the drive is on or not.

Does anyone have an example of how ths can be accomplished?

Get the Ethernet interface manual (22comm-um004_-en-p).

Read Chapter 6 on Explicit messaging. Follow the example for Get Attribute Single Message. The "Instance" will be the parameter number for 'current' on the PF400 (I don't have the manual right here).

Obviously once you have that information into the controller you will create a display for it on the panelview Plus.

Of course with that information you could write the program to take any steps necessary which may include haltinga process and displaying a warning/directive to the operator. Maybe flash some light?

Measuring motor power is more reliable than measuring just the amps. The PF400 will give you power as well as amps (I think its parameter 7 but I'm going from memory here). Power is linear with the actual load while current changes little through most of the range of the motor until it starts to approach full load and beyond.

I've done it before but I don't remember the exact procedure - you need to configure the data link so that the 22-comm-e includes power (or amps from one phase) as part of the data it sends.

On a related note, are you sure that you are looking for a current increase? In most vacuum systems when a clog occurs then the load on the motor actually drops. The blower is no longer moving any air so its not doing any work, hence the load on the motor drops. (This is the same reason why your vacuum cleaner at home speeds up when you block the hose). Naturally, we don't have the details on your system, so I'm just kicking this out there as what is typical.

Thanks bernie. I think this is what I'm looking for. This system was installed and configured before I got here so the manuals are no where to be found. I downloaded the manual you referenced and I will give this a try tomorrow.

Alaric- You're right, the amps do drop in a clog situation. Mis-type on my part. I will give the power some more thought though... It might be a better way to go.

Thanks guys!!

Take a look at this example. I cut and pasted it out of another project so its not fully complete, but it shows the basics of how I set up messaging with one drive to fetch 8 different words of data one at a time using a loop and an array to fetch the data approximately once every 3/4 second.

I hope it helps. Its in V16.

Okay, that works... But reading the power IS more useful! I am now monitoring the power and firing an output to remove the tube from the product bin with a pneumatic cylinder before a clog occurs. I also put a power usage display on my HMI. I think I might put an auto/manual mode in too.

Either way, thanks a lot!! (Especially for the example, like most people, I learned this stuff by disecting and figuring out the work of a "real programmer".)

Thanks again!