I oversee the maintenance of a few imported automatic assembly machines. Each machine has 40-70 Festo air cylinders, and each cylinder has two to four 3-wire Festo reed type cylinder position sensors. The machine produces about 30,000 parts per day. I have found that these cylinder position sensors are the source of many of our previously unexplainable intermittent breakdowns. The sensors fail despite the status indicator reporting all is good. I have also determined that their mechanical nature might be negatively affected by the rough operation the sensors experience. The machine manufacturer likes to have cylinders operate line pressure, at high speeds and without cushions at the end of their stroke. I refer to the setup as "everything set to kill"
As a test, I recently switched a few sensors to Sick and Balluff solid-state cylinder position sensors. These appear to function flawlessly. My question is, other than to have a dry contact, why would someone specify the reed type over solid-state? Cost and not needing to stock both NPN and PNP are the only reasons I have received when asking vendors & peers.
Are there other reasons to select one type over the other?
Thanks
Andrew
As a test, I recently switched a few sensors to Sick and Balluff solid-state cylinder position sensors. These appear to function flawlessly. My question is, other than to have a dry contact, why would someone specify the reed type over solid-state? Cost and not needing to stock both NPN and PNP are the only reasons I have received when asking vendors & peers.
Are there other reasons to select one type over the other?
Thanks
Andrew