Micrologix 1100 high speed counter issue

[ALT]

Hi Everybody.I have little bit experience in HSC in micrologix.I have high speed pulses input from weightometer given to HSC of micrologix.My problem is i am getting the pulses but they are updating with jumping values in panelveie 1000 pluse,like pulse will update 3-4 values at a time.The panel 1000 is connected to the Ethernet communication of the micrologix.it is major issue to the process as they need to load the material very precisely so jumping of counts is making it difficult.Is it with counting issue of the micrologix issue or update time of the panel view screens,as i have set the screen scan to min of avialable 0.05 sec.Please anybody help me out i am struck at site.

Thanks in Advance.

 

[bernie_carlton]

As long as the micrologix is controlling the operation based on the counts then it should not be a problem. But if some other device is controlling it based on what value is read from the micrologix then you may have problems.

 

[ALT]

There is no other device controlling it only thing is the operator has to press the button to change the wagon while loading with some particular value.Please anybody help me i am seriously struck with this problem.

 

[kolyur]

It sounds like your HSC is working correctly. What I'm hearing you say is that the Panelview display doesn't update fast enough and this makes the job harder for the operators. I think you're out of luck with the hardware you currently have. When it comes to display update speed, the Panelviews seem to be on the low end of all the HMI's I've used. You could try a different brand of HMI and/or a different comm connection (i.e. point-to-point RS232 with high baud rate). If you have the hardware available, you could feed an analog output from the PLC into a digital panel meter with scaling capabilities.

EDIT: In your last post you said the operator has to push a button when the weight reaches a certain value. Why not just have the PLC control this function? Have the operator enter a target weight on the Panelview and the filling operation (or whatever it is) will stop when the HSC reaches the target.

 

[ALT]

Thanks for the Reply.As i cant put the weight of loading because it keeps on changing.Will using serial RS-232 will sort out my problem.Please suggest me on this issue

 

[robertkjonesjr]

I have run into this before - when I desire a very fast screen update rate I avoid communication links like ethernet and serial. I usually go with one of the PLCs with a built-in HMI for this particular function. I find the comms delay significantly less that way.

 

[kolyur]

Will using serial RS-232 will sort out my problem.

Possibly, but I don't think you'll ever be satisfied with a Panelview if you need a quick update rate. I have found that the Red Lion G3 screens update pretty fast, especially if you use 38.4k RS232 and have minimal objects on the screen at any one time.

 

[ElectricFreak]

From your description I assume the operator is controlling a product dispensing feed point with a on/off button switch.
Can you setup a second button to run the feed at a much slower rate?
So the operator runs the output at high speed until they are within a lb and at slower speed to finish off to exact weight..

 

[ALT]

I have observed that in plc logic also the update is jumping sometimes with two values.I have kept the scan time(filetr) as defualt shall i have to reduce in micro seconds ?AS i am having the AB panelview 1000 plus i cant change the hardware.Please anybody can suggest for the scan time of plc and panel view to update the tag values faster i cant leave this issue in process plant,it will be a big mess in loading of the weight.

 

[OkiePC]

Why not have the operator enter the target weight, and let the PLC control the process to achieve the weight?

Another thing to check if they're using a momentary button to "jog" a feeder, make sure the on time setting for the Panelview button is set to the minimum...

 

[ALT]

They does't to control by giving the weight because it will change in every wagon.The only intension of the operator is he can see each and every pulse but not jumping values.Panel view should update with each pulse trigerred in PLC.

 

[kolyur]

I have observed that in plc logic also the update is jumping sometimes with two values.

Remember that when you are viewing the program online, you are also seeing the result of a communication lag just like the Panelview does. If the count jumps from say 120 to 122, the value of 121 did in fact occur and the PLC registered it, but it was too fast to be shown in RSLogix.

I have kept the scan time(filetr) as defualt shall i have to reduce in micro seconds

Yes that is usually necessary when you are using an input for high-speed counting. You will need to know the maximum pulse rate in order to determine the proper setting.

Please anybody can suggest for the scan time of plc and panel view to update the tag values faster i cant leave this issue in process plant,it will be a big mess in loading of the weight.

You need to rethink how you are doing this. I'm sorry to say, but there isn't some magic parameter in the Panelview or PLC that you can switch to make it update faster. Panelviews are slow, period.

They does't to control by giving the weight because it will change in every wagon.

So what? Why can't s/he update the target weight between every wagon? Let the PLC do all the work. You'll end up with more accurate fills this way than if you're relying on a person standing there pushing a button.

 

[ALT]

Controlling from plc is not possible here because there is some issue with the plant engineers they dont want it.Pulse rate here is 1800 per minute so i have kept the input filter as 1 ms first but still the problem is same now i want to put the iinput filter to 25 micro seconds so that it will update fast, anybody suggest for this is it recommended or not.

 

[CroCop]

ALT, my dude, tell the plant engineer that it's not capable of being improved that way. The best & only way is to enter the weight & let the automation do it, not the person.

 

[CroCop]

You will not get the HSC to trigger off of an operator release in sync with the panelview. It simply WILL NOT happen.