Samsung SSAS21-DI Digital Input Module



Samsung SSAS21-DI Digital Input Module is a high-density discrete signal input module designed for the Samsung SSAS21 programmable logic controller (PLC) and industrial automation platform. Built to capture digital status signals from field sensing devices, the SSAS21-DI converts raw binary inputs into isolated logic states processed directly by the central CPU.

Technical Parameter List

Core Advantages & Product Features

High Noise Immunity: Optocoupler isolation barriers physically separate field signal paths from internal backplane micro-logic, preventing transient surges from causing logic errors.

Fast Response Switching: Low input latency allows accurate detection of high-speed limit switches, optical encoders, and sensor pulses.

Real-Time LED Diagnostics: Individual channel LEDs display incoming signal states instantly, shortening electrical troubleshooting time during panel commissioning.

Flexible Wiring Formats: Compatible with both Sink (NPN) and Source (PNP) field wiring configurations for broad compatibility with sensor brands.

Robust Hardware Filtering: Built-in debounce filters eliminate contact bounce false triggers from mechanical relay contacts and switches.

Model Classification

SSAS21-DI: Standard 24V DC Discrete Digital Input Module.

SSAS21-DO: Discrete Digital Output Module (Relay/Transistor output interface).

SSAS21-AI: Precision Analog Input Module (4–20mA / 0–10V process inputs).

SSAS21-CPU: Central Processing Unit Module for the SSAS21 series architecture.

SMTB-DI: External DIN-Rail Digital Input Terminal Board (Used for external terminal routing).

Environmental Tolerance Conditions

Operating Temperature: 0°C to +55°C (32°F to 131°F)

Storage Temperature: -25°C to +70°C (-13°F to 158°F)

Operating Relative Humidity: 5% to 95% RH (Non-condensing)

Vibration Resistance: Conforms to IEC 60068-2-6 (10–57 Hz @ 0.075mm, 57–150 Hz @ 1.0g)

Shock Immunity: 15g peak acceleration, 11 ms duration (IEC 60068-2-27)

Enclosure Protection: IP20 (Must be installed in an IP54 or higher control cabinet)

Installation Method

Power Isolation: Shut off main power to the SSAS21 rack before inserting or removing the module.

Backplane Insertion: Align the rear guide rails of the SSAS21-DI module with the target slot on the SSAS21 base chassis. Press firmly until the module locks into the backplane connector.

Module Retention: Tighten top and bottom panel retention screws to secure the module against vibration.

Field Cable Connection: Attach the pre-wired terminal block to the front interface connector and secure terminal locking screws.

Operating Instructions

Field Wiring Selection: Ensure external 24V DC sensor power supply common (0V/V+) is correctly jumpered for Sink or Source configuration.

Signal Voltage Verification: Maintain input signal voltages within 18V DC to 28.8V DC; voltages below 11V DC may register as logic "0".

Routine Maintenance: Periodically check terminal connections for tightness and clean dust accumulation from chassis ventilation slots.