Channel limition an groups.

[**Madman**]

We designed a system to log data using TDMS files with the intention of using DIAdem 2015 to examine the data. Our system has grown to record a couple thousand channels of data, which is well below the 65000 channel limit. However, every time we stop and restart testing we create a new group that uses the same channel definitions, as a means of keeping track of the different tests intervals, and splitting up the data into manageable chunks. Unfortunately it seems that for each group even though the channels are the same it is treated as a new channel in DIAdem. So in our scheme if we have 2000 channels then DIAdem will only load the first 32 groups. Is there an easy way to tell DIAdem when file is loaded to load a range of groups? I.E. group 33-64, 65-96 etc. or do I need to split up the TDMS file into multiples of groups that fit into the channel limit of DIAdem? I have seen that DIAdem 2019 allows 150,000 channels which would extended our group count but still be limited.

[Walter_Rick]

Hi **Madman**,

DIAdem 2015 can manage a maximum of 65535 channels. It is independent whether you have this number of channels in one channel group or more. (The maximum number of channel groups is also 65535.)

Since DIAdem 2019 SP1 the maximum number of channels is 150000.

In your example this means, 32 channel groups with 2000 channels each are 64000 channels, and a rest of max. 1535 channels is available.

With DIAdem 2019 SP1 or later you can load up to 75 channel groups with 2000 channels each.

In the end this means that you need to split your TDMS file into several files with a reasonable number of channels and channel groups, respecting the limits describes above.

Greetings

Walter

[Brad_Turpin]

Hey Madman,

Would it help to load the data in your TDMS file into one concatenated Group of really long channels, or do you need to preserve the start and stop segmenting of the data?  What do you want to do with this data once it's loaded into DIAdem?  Do you want to plot the overall trends of all the Groups on one graph, or do you want to perform calculations on the data in each Group and then show those Group-by-Group results in graph of roll-up results?

I think it's likely that there's a way to finesse the loading and calculating that you need to do (with a script) so that you don't need to have all the Channels from your TDMS file loaded in DIAdem all at the same time.

Brad Turpin

Principal Technical Support Engineer

NI