How to use user set type with VC4 trends

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1

Hi, has anyone got trends to work with User set as the type?

Type

All the following help seems to only apply to online, and I have tried different options and can’t get it to work. For context, I have a curve of machine speed against output and would like to display it on the HMI. I have found that I can run an online trace after boot and show that, but it’s a bit of a fudge

Thanks, Brian

2

Hi Brian,

Of course the User type works correctly.

I guide you a bit:

When selecting ‘User’ mode, one of the following parameters must be configured: “SampleRate” or ‘SampleRateDatapoint’, which represent the difference in milliseconds between samples. If you decide to configure ‘SampleRateDatapoint’, this will be used instead of ‘SampleRate’.

For this type of graph, is better to use using the ‘Mode’ single.

image

You can also choose the number of vector elements to be displayed using the ‘SampleCountDatapoint’ parameter. It is also possible to define the time of the last sample with the parameter ‘SampleDateTimeDatapoint’. If this parameter is not configured, the first element of the vector will take the time 0 and the last will take the time given by its number within the vector multiplied by ‘SampleRate’ or ‘SampleRateDatapoint’ (whichever is being used).

For example: If you are using SampleRateDatapoint, the element number ‘i’ within the vector will have an associated time (its coordinate on the X-axis in the graph)

T = i · SampleRateDatapoint.

Hope this helps.

Xabier

3

Thanks Xabier, you are correct if I make a new empty project

If I try to change my existing project, it doesn’t work and sometimes will crash VC in the PLC - current page data point stops updating etc.

I have tried making a new trend in my existing project, but that doesn’t work either

Brian

4

Found that if I use the trend wizard, it works, but if I edit an existing. it doesn’t

Thanks