When designing industrial control circuits inputs and outputs may seem pretty obvious. But beyond the standard digital I/O we have experience with many other types of I/O that often come with challenges. We design projects with all types of I/O configurations available, including digital, analog, encoder, thermocouple and others. Many aspects of designing I/O are often overlooked, for example when designing analog I/O the challenges of wiring the circuits is not often considered. 
Not only do we take into account the electrical characteristics but also the physical characteristics for real world applications. We look at how far back the insulation has to be removed in order for the shield to reach the tie point, how many shields go to a point, how do they need to run in the panel for isolation from high power, and the bundle size.
When designing an encoder circuit we review the encoder location, connectors, interface points and how all that gets physically wired. For designing circuits that require thermocouples and RTD’s we will review the accuracy requirements to determine if specialty terminal blocks are necessary. For example a type J thermocouple requires a different terminal block than a type K thermocouple in order to 
maintain the proper metallic properties of the termination required for accurate readings. These and many other experiences our put into out I/O designs.
