Tip of the Day 47: The Practical View

The Lynx Port Limits described in Tip # 46 are an answer to the question “How many can you hook up and have the eDART still read them?” The 30 / 14 limit is based on the protocol and the power available. However they do not address how many sensors are practical and usable.

With the original eDARTs shipped until Spring of 2007 the processor speed made hooking all 60 sensors to the eDART impractical. First the startup time became extraordinary. Once started the drawing of the cycle graphs was slow enough that they might not get finished before the machine cycled again. Fortunately all of the controls, computations and alarms run at high priority so the eDART would not miss much as long as you waited for the job to fully start before running the machine.

In light of this we have made it a policy to recommend only 16 cavity sensors be hooked up at one time. Anything beyond that should trigger a request to RJG engineering to become involved in deciding whether a specific application will work with more. We have run up to 36 sensors successfully with the slower eDART.

With the release of the faster the startup speed issues are much reduced, if not eliminated. So far testing has shown good performance with up to 40 sensors. However the Cycle Graph screen can still be VERY busy with many curves on it, even if it can draw them all. We are thinking of some tools that would make high cavitation applications much easier to visualize (ideas are welcome). In the meantime, refer to Tip #23 on the “Phantom” curves for methods for simplifying the Cycle Graph view.


Sample Rate spreadsheet