Tip of the Day 20: Fail-Safe Sorting Revisited or “The Case of the Missing Sensor”

If a sensor on the eDART is not communicating or has failed, how do I ensure that un-checked parts do not get out to the customer?

Elementary, my dear Watson

The eDART Alarm Settings tool will show the part as suspect, now displayed as Warn?. For the diverter output this is just like a warning. We don’t know whether the part is good or not so it turns off both the Good output and the Reject output.

This makes fail-safe (using the Good output) very important. If you want to prevent a bad part from going out because of missing data then you must use the Good output. If the robot will not accept a contact closure for “Good” then name the sorting output Good anyway and wire the robot to the normally closed contact on the OR2-D.