Samsung SSAS21-CPU Central Processing Unit Module



The Samsung SSAS21-CPU Central Processing Unit Module serves as the primary processing engine for Samsung's SSAS21 industrial automation and PLC control platform. Engineered for real-time control, process automation, and high-speed data execution, the SSAS21-CPU coordinates field I/O modules, manages system communications, and executes complex logic routines in harsh industrial environments.

Product Introduction / Overview

The Samsung SSAS21-CPU is designed to deliver high-performance logic processing and system stability for automated assembly lines, manufacturing equipment, and infrastructure control systems. It features built-in self-diagnostics, multi-protocol communication support, and solid-state non-volatile memory to prevent program loss during total power outages. Its modular design allows seamless integration with SMTB series terminal boards and SSAS21 expansion racks.

Technical Table

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)

Relative Humidity: 10% to 95% RH (Non-condensing)

Vibration Immunity: 10 to 57 Hz @ 0.075 mm amplitude; 57 to 150 Hz @ 1.0 g acceleration

Noise Immunity: Noise voltage 1500 Vp-p, pulse width 1 µs via noise simulator

Enclosure Protection: IP20 (Requires mounting inside an IP54-rated industrial cabinet)

Operating Instructions

Pre-Power Inspection: Ensure the CPU module is firmly seated into Slot 0 of the SSAS21 backplane chassis and the locking mechanism is engaged.

Program Download: Connect the programming terminal to the CPU port (RS-232/RS-485) and transfer the control ladder logic/configuration.

Mode Selection: Switch the physical keyswitch/toggle on the front panel from STOP/PROGRAM to RUN mode to begin logic execution.

Battery Replacement: Replace the internal lithium backup battery while system power is ON to prevent SRAM program memory loss during planned shutdowns.

Fault Diagnosis & Troubleshooting

ERROR LED Solid Red: CPU execution halt due to critical system error (checksum error, watchdog timer timeout). Cycle power; if persistent, re-download the ladder program.

BATTERY / BATT LOW LED On: The internal memory backup battery voltage has dropped below operational thresholds. Replace with a standard Samsung lithium battery module.

COMM / TX/RX LED Off: Check communication cables, terminal resistor settings, and baud rate parameters between the CPU and host system.

I/O BUS Fault: Verify backplane connectors for bent pins or contamination; ensure all expansion modules are securely locked into the rack.

Related Models in the Same Series

SSAS21-PWR: Main Power Supply Module for SSAS21 rack chassis

SSAS21-BASE: Multi-slot Expansion Backplane Base Unit

SMTB-DI: Digital Input Terminal Board interface module

SMTB-DO: Digital Output Terminal Board interface module

SMTB-AI: Analog Input Signal Conditioning Module

SMTB-RTD: RTD/Thermocouple Temperature Input Board

Storage Conditions

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

Humidity & Atmosphere: 5% to 95% RH non-condensing in a corrosive-gas-free environment.

Packaging Protection: Keep sealed in original moisture-barrier ESD safe bags with desiccant until final installation.