I’ve been talking pneumatic systems (valves, cylinders, actuators, etc.) recently with my customers and I’m finding among these engineers some common pains coming out of the system design. It seems that many people are researching networked valve islands with I/O built-in. These seem to be a great way to consolidate lots of I/O into one IP address, but there are some new issues cropping up similar to the above photo:
- When assembling these at a machine builder the routing of cables with piping is more cumbersome with cables hanging off the valves, larger cable tray installations and large amounts of piping all running to the same spot.
- For machine builders, with all of the valves centralized in one place, the pneumatic lines have to be longer. This causes many issues such as slower responsiveness due to air volume, air inertia, and lower air quality.
- When trying to perform maintenance at an end-user, it becomes a nightmare to troubleshoot with a cluster of cables and pipes. The zip-tied and clean runs installed by the machine builder are cut, tangled and re-routed as the machine ages and becomes more difficult to troubleshoot.
- Also at end users, if the manifold needs to be expanded, updated, retrofitted with new valves or I/O, there are big hurdles to jump when doing this: re-piping the valve due to mounting position shifting or even having to edit and repair code in the PLC to adapt to new bitmaps generated by the new valve manifold configuration.
- When closing the loop with magnetic field sensors mounted on the cylinders, typically reed switches are used which are prone to failure. In addition, these switches typically have two sensors & cables per actuator to give extend or retract position, these cables cause larger cable trays and long cable runs back to the centralized manifold and I/O.