PLC - What Is An Analog Module And How It Work?

PLC - What is An analog module and How It work?

Published on Mar28, 2023 | Category: Introduction

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sensors like thermocouple, RTD, Level transmitter etc., have a continuous or variable signals. Which are also knows as analog signals. These analog signals represent a real-world physical quantities. For reading these analog signals in PLC required special type of hardware which is known as analog module. analog input module are basically use Analog-To-Digital Converter (ADC) for converting analog signal into the digital signal. Analog Output Module use Digital-To-Analog Converter (DAC) for converting digital signal into analog signal. These module perform amplification, filtering, signal conditioning so we receive a proper and exact value. analog input module, used for reading analog signals from sensors or other devices, analog output module, used for sending analog signals to devices. Analog modules in PLCs either integrated into the PLC or connected externally via expansion modules. The number of analog input and output channels can vary depending on the specific module and application requirements.

What are the types of analog modules in PLC?

classificaltion of analog module depends on plc application and type of analog signal being processed. as we know that now a days plc are used for their accuracy, speed of processing. as discussed alredy we can use analog module as input and output. so following are common plc analog module

input/output modules (I/O modules): These are combination of analog input and output channels in a single module. They are useful in applications where both input and output channels are required.
High-speed analog modules: they used high-speed sampling and processing for analog signals. They have faster conversion as compared to normal analog module.
RTD Modules : these modules only used in resistanse temperature detector.
thermocouple modules : used for thermocouple as we know that thermocouple output in millivolt.
Strain Gauge modules:these modules are used to measure mechanical strain using analog sensors such as strain gauges.
Current & voltage measurement modules:These modules are used to measure current and voltage using analog sensors.

types of analog signal in plc ?

Programmable Logic Controller (PLC) analog module processed signal using different voltage or current levels. These levels of analog module is input or output of module. all analog input and output is a basically some fixed range of current or voltage. These fixed range of voltage or current converted into digital data which represent real value these real value converted into actual value by using scaling instruction. They have some specific range which we discussed below

4 to 20 mA analog signal : this is most commonly used analog signal. The signal is typically transmitted as a current range from 4mA to 20 mA.4mA representing the minimum value and 20mA representing the maximum value.
0 to 10 VDC analog signal:it is voltage signal which transmitted 0 to 10 VDC.0VDC representing the minimum value and 10VDC representing the maximum value.
± 10 VDC analog signal:This standard uses a voltage range of ±10 volts DC, with a midpoint of 0V. The negative voltage represents the minimum value, and the positive voltage represents the maximum value.
± 5V DC analog signal:This standard uses a voltage range of ±5 volts DC, with a midpoint of 0V. The negative voltage represents the minimum value, and the positive voltage represents the maximum value.
1 to 5V DC analog signal:1-5V DC: This standard uses a voltage range of 1 to 5 volts DC, with 1V representing the minimum value and 5V representing the maximum value.

what is Channels in analog modules

input and output channels allows plc to send or recives signal from sensors. generally analog module have 4 channels, 8 channels, 16 channels analog module. The specific type of module and channels needed will depend on the application and the specific requirements of the system being controlled.