OVERVIEW

Basic Details: LYA010A Input/Output Module HITACHI

1 PLC Input/Output Modules

Introduction 1.1 Digital and Analogue Signals

Digital input/output signals are switching signals, a 1 or a 0.

Analogue signals, there are two kinds of voltage signals or current signals, generally signals transmitted by the transmitter, such as pressure transmitter to detect the pressure of the water pipe, will output a 4-20ma or 0-10V analogue signal to the PLC, the PLC for data processing.

Switching input point (DI), processing switching input signal.

Analogue input point (AI), processing analogue input signals (0-20 MADc, 0-5VDC).

Resistance signal (including RTD) input point, processing RTD or general resistance signal.

High-speed pulse input point, processing high-speed pulse signals.

Voltage (including thermocouple) input point, processing voltage input or thermocouple signals.

There are also communication functions for data exchange with the host computer or control subordinate controller instrument driver

1.2 Digital and analogue input modules

According to the different field input signals, the input module can be divided into switching input module and analogue input module.

The function of the switching input module is to convert various switching signals into TTL standard signals required by the CPU. Depending on the type of input power supply, they can also be DC input modules and AC input modules. The input signals are converted to TTL (5V) standard signals by photocoupling after voltage division, current limiting, and filtering.

The function of the analogue input module is to convert www.cniacs.com changing analogue signals such as temperature, flow, current, voltage, etc. into a number of digital signals which can be processed by the CPU. The analogue input circuit is generally composed of operational amplifier conversion, mode conversion (A/D), and optoelectronic isolation.

PLC input and output module types: digital input DI, digital output DO, analogue input AI, analogue output AO.

Digital inputs and outputs are generally 24V.