Multiple Cylce Modifiers?

In the graph editor I’d like to start an animation, then stop it. Then some time later start and stop it again.

I’ve tried adding a second Cycle modifier to the channel, but I get a message saying Cannot add modifier, see console for details, but there are no details in the console. So should this be possible? If so how do you go about it.

If not possible, how do I get around this? I don’t really want to cut the project up into sub projects for rendering.

Thanks.

Similar question here https://blenderartists.org/forum/showthread.php?414911-Vibrating-a-curve&p=3146772&viewfull=1#post3146772

Hmm, It’s not quite the same, but I might be able to make it work. I’ll start a test project.