There are better alternatives to detect pneumatic cylinder end of stroke position than reed switches or proximity switches. By better, I mean they are faster and easier to implement into your control system. In addition, you can realize other benefits such as commonality of spare sensors and lower long-term costs. So what are the better solutions?
In most industrial applications 80-90% of the I/O going back to the PLC is discrete points. Multiple times I have been asked, “How can I easily, quickly, and cost effectively get one channel of analog back to my PLC”. The solutions in the past have either involved an IP20 slice I/O solution in a J-box, which is expensive and labor intensive, or an IP67 network module, which reduces labor costs but still carries a high cost. A common drawback to these solutions is that you have to pay for 2, 4, or even 8 channels when only one is required.