Problem with keeping Multiple Limits for one input field

[ernitin29]

Hi Guys,

I have got a problem regarding the setting of more than one limit for one input field. I have got four motors for extrusion & One for Hauling (Pulling a plastic pipe)

I am working in WINCC Flexible Advance

if i need to change the hauling speed, it is also required to change the speeds of the four motors. for this purpose I use synchronisation. the max hauling limit is 11.55 mtrs/sec
and also there are certain limits of other motors.

i have already done the min max limit for the input field of hauling but when i am using synchronisation it is required to set the new limit of the same input filed which would be not more than 11.55 but little less than 11.55. for that i have to put the another additional limit. I have tried something like additional limit, some vb script stuff etc. but nothing works

Can somebody help me out...deadline is just about next corner

help me out....



Thanks

 

[Anirban Hazra]

if i need to change the hauling speed, it is also required to change the speeds of the four motors. for this purpose I use synchronisation. the max hauling limit is 11.55 mtrs/sec
and also there are certain limits of other motors.

i have already done the min max limit for the input field of hauling but when i am using synchronisation it is required to set the new limit of the same input filed which would be not more than 11.55 but little less than 11.55. for that i have to put the another additional limit. I have tried something like additional limit, some vb script stuff etc. but nothing works

I may have misunderstood what you want to say,but I derived from your explanation that the Hauling motor can be run at 11.55 m/s max when not synchronizing with the other motors, and at a lower speed when synchronizing with them.

You can do this by doing the following:
1.Make a bit high when "Synchronization" is selected from a Field/HMI input.
2.Place the two Limit functions in parallel in your appropriate rung.
3.Place NC of the "Synchronization bit" in front of limit containing max as 11.55 m/s
4.Place NO of that same bit in front of the other limit having max less than 11.55 m/s

Doing the above will ensure that proper limit is applied to same field input depending upon whether "Synchronization bit" is high or not.

(Note: I have assumed that your program is written in a way such that synchronization has to be selected.If your program is such that the synchronization occurs automatically when certain conditions are met then you just have make the "Synchronization bit" high when these conditions are met.)
​

 

[moggie]

Hi Guys,

I have got a problem regarding the setting of more than one limit for one input field. I have got four motors for extrusion & One for Hauling (Pulling a plastic pipe)

Thanks

Try carrying out the limit check in your PLC Program OR use PLC Tags for "Upper" and "Lower" limits for your Wincc Flex input.

 

[ernitin29]

hiii

Try carrying out the limit check in your PLC Program OR use PLC Tags for "Upper" and "Lower" limits for your Wincc Flex input.

Hi....

Thank you for your reply.

As I mentioned that these limits that you mentioned here, have already being used as lower limit : 0, Upper Limit : 11.55 when synchronisation is not under operation. But when syn is on lower limit remains same and higher limit changes and the value of this limit is in another tag. That's why it is required to put the another limit for syn function.

I couldn't find out the solution, but one thing for sure that, as it is associated with the syn. That means when i press syn on button, this tag which sets the different limit must replace the limit 11.55. And that can be done by vb script.

Let me know if u get something, me too will do same if ill get it.

 

[moggie]

Try this in the PLC
please note I do not know what tags you are using so you must change the M & MD's I show to your tags.

 

[ernitin29]

Try this in the PLC
please note I do not know what tags you are using so you must change the M & MD's I show to your tags.

I have already a location VD8028, in which calculated upper limit real value is there but i have got the problem to put this limit in my wincc program, where to put this as i have already put the 11.55 as constant in upper limit when syn is not on.

 

[moggie]

I have already a location VD8028, in which calculated upper limit real value is there but i have got the problem to put this limit in my wincc program, where to put this as i have already put the 11.55 as constant in upper limit when syn is not on.

Look at post 3 and create a Tag for the upper limit instead of a constant.
I assume that you are using Microwin and not S7 Simatic Manager I used for my example.