PLC Special Inputs and Outputs

Hi friends, I hope all of you are enjoying your life. As you already know, we have started a series of PLC articles. In the last lecture, we studied a detailed article on PLC discrete inputs and outputs. In today’s tutorial, I am going to explain to you a detailed article on PLC special inputs and outputs.

In the last lecture, we discussed that a PLC has different inputs and outputs that are already assembled on PLC modules that are known as PLC fixed modular. We also discussed some discrete inputs and outputs that are not connected with it, but we can connect them with a PLC according to their use, like pushbuttons, relays, motors, etc. But some input and output devices enhance the capability of the PLC and are used only for some special purpose. These are known as PLC special devices, which enhance PLC values in industries and different projects. As it reduces the cost for other devices because it already has the capability for these devices, which have to be purchased separately. In this article, we will discuss them in detail. I hope you will get a lot of knowledge about these instruments and will work properly on plc. So let’s get started with PLC special inputs and outputs.

PLC Special Inputs and Outputs

• Many different types of input and output modules have been designed to fulfill special requirements.
• These are described and listed here.
  • PLC HIGH-SPEED COUNTER MODULE
  • PlC THUMBWHEEL MODULE
  • PLC TTL MODULE
  • PLC ENCODER-COUNTER MODULE
  • PLC BASIC OR ASCII MODULE
  • PLC STEPPER-MOTOR MODULE
  • BCD-OUTPUT MODULE
  • Plc PID MODULE
  • PLC MOTION AND POSITION CONTROL MODULE
  • PLC COMMUNICATION MODULES
• Now we discuss all these devices in detail.

PLC High-Speed Counter Module

• The higher velocity counter unit is used to deliver interfacing for such applications that require counter velocity, which exceeds the competence of the Programmable Logic Controller ladder program.

• These counter units are used to sum pulses from sensing devices, encoders, and switches that operate at higher speeds.

• They have the electronics needed to sum individually from the CPU. A characteristic sum rate offered is zero to a hundred kilohertz, which shows that the unit would be capable of summing 100,000 pulses in one second.

PLC Thumbwheel Module

• The thumbwheel unit of the PLC permits the use of thumbwheel buttons for adding data to the PLC controller to be used in the controlling process.

PLC TTL Module

• The TTL (transistor-transistor logic) unit permits the sending and receives of TTL signals.

• This unit permits other units that generate TTL (transistor-transistor logic) level signals to connect with the CPU of the PLC.

PLC Encoder-Counter Module

• An encoder unit of PLC permits the operator to observe the signal by an encoding device on an instant basis and retains this info so it can be observed after some time by the processor.
  

PLC Basic Or ASCII Module

• The BASIC or ASCII unit of the PLC operates operator-inscribed BASIC and C language programs.
• These programs do not depend on the PLC’s CPU and deliver informal, fast interfacing among distant external devices and the PLC CPU.
• Distinctive uses contain interfacing with bar code readers, automatons, printing devices, and presentations.

PLC Stepper-Motor Module      

• The stepper motor unit sends the pulses to the translator of the stepper motor. That allows the controlling of the stepper motor.

BCD Output Module

• The BCD (binary coded decimal) output unit permits a PLC to control components that need BCD (binary coded decimal) signals like 7- segment.

• Some distinct units are mentioned as intellectual input and outputs since they have their own central processing unit on a panel that can operate in parallel with the PLC controller.

PLC PID Module

• The proportional-integral-derivative (which is an abbreviation of PID) unit is used in process controlling uses that integrate PID (proportional-integral-derivative) algorithms.
• An algorithm is a multifaceted program which founded on mathematical measurements.
• A PID (proportional-integral-derivative) unit permits process control to take place the outer part of the processor.
• This procedure stops the processor from being loaded with complicated measurements.
• The main purpose of this unit is to deliver the controlling act essential to uphold process parameters like temperature, movements, level, or velocity within set restrictions of a stated set point.

PLC Motion and Position Control Module

• Motion and position controlling units are used in applications including precise higher velocity machining and wrapping processes.
• Intellectual place and motion controlling units allow PLC controllers to govern stepper and servo motors.

• These schemes need an effort, which comprises the electronics circuitry that interprets the signals from the PLC unit into signals essential to the motors.
• The given diagram shows the plc servo module.

PLC Communication Modules

• Serial communications units are used to create point-to-point networks with other intelligent components for the interchange of pieces of information.
• These connections are usually recognized with processors, operator positions, process controlling schemes, and other PLC controllers.
• Communication units permit the operator to link the PLC controllers to higher-speed resident systems, which can be unlike the system statement delivered with the PLC controllers.

I have also uploaded some related articles on PLCs you must read them for further learning.

• Introduction to PLC
• Working of PLC
• Parts of PLC
• Input and Output Section of PLC
• PLC Discrete Input and Output Devices
• Analog Input and Output Devices of PLC

That’s all about PLC Special Inputs and Outputs if you have any questions about it ask in comments thanks for reading. See you the next tutorial Features of PLC Inputs and Outputs.