Practical Tips and Techniques
Proximity (Capacitive, Inductive), Photo electric (Thru beam, Retro Reflective, Diffuse), Ultrasonic, etc. Sensors can be either discrete (On/Off) or Analog outputs.
The BRX Do-More series of programmable logic controllers has built in high speed inputs and outputs. Every CPU will have either 6 or 10 high speed inputs (HSI) available depending on the model. These inputs can be used for input frequencies from 0 to 250Khz. 250Khz represents 250000 input counts per second that can be … Read more
The SOLO Temperature Controller is a single loop dual output process temperature controller that can control both heating and cooling simultaneously. It is available in 1/32, 1/16, 1/8, and 1/4 DIN panel sizes and is UL, CUL and CE approved. The name of the temperature controller is deceiving. This unit will also accept voltage and … Read more
We will create a simple and inexpensive analog voltage tester for a PLC using a potentiometer and a 9VDC battery. The potentiometer will be 5K ohms. This should be enough impedance for most analog inputs of the programmable logic controller. (PLC) Voltage impedance for analog voltage inputs is in the megaohm range where the current … Read more
We will now look at the parts of a PLC system. When I was in school PLCs were just in their infancy. We were taught that the PLC consisted of the central processing unit (CPU), analog and digital inputs, and outputs. Everything was programmed with dedicated handheld devices and/or software devices on specialized hardware. We … Read more
We will look at a PLC basic tutorial of a paint spraying station. Following the five steps to program development, this PLC programming example should fully explain the procedure for developing the PLC program logic. Ladder logic will be our PLC programming language. We will use the Do-more Designer software, which comes with a simulator. … Read more
We apply the five steps of PLC development to a plc shift register example. This PLC programming example will use a shift register to reject a product on a conveyor. When programming a PLC, you need to track what has previously happened. Shift registers allow you to do just that. We will look at a … Read more