Increasing frequency results in unexpected behavior of generated signal

[Mike310]

I am generating a composite signal using a sawtooth and square wave, which results in the desired signal as shown on the left. Unfortunately, when increasing the frequency past 1Hz, I get undesired results as shown on the right.  

        

I have attempted to alter the sampling info with no luck. I have also attempted differing methods to produce the desired signal. I have noticed that before one of the partial components of the final signal enters a relay, the increase of frequency does not create any unexpected results. Although, after it has passed through a relay, the error begins to occur. This seems like the relay is not suited for higher frequencies, but I am unable to correct for this unexpected behavior. 

Frequency of 1 Hz:

Frequency of 3Hz:

An alternate method I had attempted was to use the 'Simulate Arbitrary Signal,' though I was unable to find a way to increase the resulting signal's frequency.  

Also, the signal has this grainy nature which I would like to make smooth and continuous. Is this possible? I eventually would like to reach a frequency of a few kiloHertz.

I have attached the VI. 

Any help would be greatly appreciated. Thanks.

[p-rose · Accepted solution]

The problem has to do with the block size and when the relay actually sees the sawtooth cross the threshold.

To resolve it, we have to do a point by point check and build our custom waveform on each iteration.

[Mike310]

I have been trying to fix this for days without success.

It works great now. Thanks for the help.