Anyone knows of a good way to interface 5mm range linear displacement sensor to the PLC? We need something like 0.005mm accuracy. Analog/SSI/DeviceNet would be preferable.
I've done similar applications. 0.005mm accuracy over a 5mm range is 0.1%. You should be able to do this with a 5mm LVDT and a good signal conditioner. I would recommend calibrating the system in-place, so be sure the signal conditioner is accessible. If the signal conditioner is DC powered, you may want to give it its own power supply.
Most PLCs have analogue inputs. You will need to check whether the particular PLC you are using has an analogue input card (or networked I/O block) which is good enough for this application (some of the cheaper ones have good resolution, but poor accuracy). Allow a settling time before taking a reading to allow all the mechanics and electrics to stabilise.
