Call Excess Equip at 615-613-0303
Dedicated to selling the highest quality used conveyor equipment

Using Programmable Controllers part 2

Last week we discussed a couple of the components that Programmable Logic Controllers use. We covered the Central Processing Unit (CPU) of the controller, as well as how you might mount and assemble your PLC.

In this post we will cover the assembly of the input and output of a PLC.


Inputs take information into the PLC to carry out a task by transporting signals from the process into the controller. Input types can include switches, pressure sensors, and operator inputs among others.


On the other end of the input is the output. Outputs are the devices that the PLC uses to send changes out from the controller to wherever you need. This includes features such as motors, lights, relays,  and pumps, and enable to PLC to change to adjust or control the process.

Many types of inputs and outputs can be connected to a PLC, but they essentially are comprised of two major groups – analog and digital. Digital types operate on a “yes or no” function through binary change. Analog change continuously through a wide range of variables such as pressure or temperature.

In our next post, we will cover information regarding the power supply as well as the programming device and/or software. Excess Equip carries a large selection of PLC Components that can be found here. Please feel free to call us with any questions you might have. We also carry more items than what is listed on the site, so do not hesitate to contact us if you cannot find what you’re looking for!