Description

GE IC693CPU351-DF

I. Overview

II. Technical Parameters

III. Functional Features

• Stable Computing and Control Capability: Equipped with a 16-bit industrial-grade dedicated processor with a 20MHz main frequency, the basic instruction execution time is as low as 1μs, enabling efficient processing of core tasks such as logical operations, sequence control, and data comparison. The 512KB EPROM program memory supports large-capacity control program storage and can be expanded to 1MB to adapt to complex control logic. The 32KB RAM data memory with battery backup ensures that key production data (such as cumulative output, process parameters) is not lost after power failure, guaranteeing production continuity.
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• Flexible Multi-rack Expansion Capability: It supports connecting up to 3 racks through a dedicated expansion bus, with a maximum expandable capacity of 1024 digital I/O points and 128 analog I/O points. This allows flexible adjustment of system configuration according to production scale. It is compatible with the full range of 90-30 series expansion modules, including high-speed counting modules (for speed measurement, pulse counting), temperature acquisition modules (compatible with thermocouples, RTDs), and positioning control modules. This enables rapid system function upgrades to meet different process requirements.
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• Diversified Communication and Networking Adaptability: It has a built-in RS232 communication port that can directly connect to a programming computer for program downloading, debugging, and monitoring. By expanding dedicated communication modules, it can support multiple industrial communication protocols such as PROFIBUS-DP, Modbus RTU/TCP, and Ethernet. This enables seamless data interaction with upper-level monitoring systems (e.g., GE iFIX, WinCC), HMI human-machine interfaces, frequency converters, and intelligent instruments. It supports the construction of distributed control systems to realize multi-CPU collaborative work and remote centralized management and control.
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• High Reliability and Anti-interference Design: It uses industrial-grade high-quality components and has passed strict reliability tests such as high-low temperature cycling, vibration impact, and electromagnetic compatibility (EMC). The Mean Time Between Failures (MTBF) exceeds 150,000 hours. It integrates multiple protection mechanisms, including power overvoltage/overcurrent protection, CPU overheating protection, and program verification protection. The module itself adopts a shielding design, and combined with the signal isolation technology of the backplane, it can effectively resist interference factors such as electromagnetic interference and voltage fluctuations in industrial sites, ensuring stable operation of the control system.
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• Convenient Programming and Diagnostics Functions: It supports program development using GE Fanuc dedicated programming software (e.g., Cimplicity Machine Edition, VersaPro) and is compatible with international standard programming languages such as Ladder Diagram (LD), Function Block Diagram (FBD), and Structured Text (ST). It has a built-in rich library of industry-specific functions (e.g., PID regulation, counters, timers), which greatly improves program development efficiency. It is equipped with comprehensive self-diagnostic functions that can real-time monitor the operating status of the CPU, memory, expansion modules, and communication links. When a fault occurs, it outputs a fault code through the flashing of the panel indicator light and stores the fault information in the internal register, facilitating engineers to quickly locate and troubleshoot problems.

IV. Working Principle

1. System Initialization Phase: After the CPU is connected to the DC 5V power supply through the system backplane, it immediately enters the initialization process. First, it performs a self-test on its core components (processor, memory, built-in communication port) and simultaneously detects the model and connection status of the connected expansion racks and expansion modules. If the self-test passes, the "RUN" indicator on the CPU panel remains on, and the control program in the EPROM is loaded into the RAM memory. If the self-test fails (e.g., memory fault, abnormal connection of expansion modules), the "FAULT" indicator flashes and outputs the corresponding fault code, the system pauses operation and stores the fault information.
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3. Signal Acquisition Phase: After initialization is completed, the CPU interacts with each expansion module through the backplane bus at a preset cycle (minimum 10ms) to collect on-site industrial signals. The digital input module collects the switch status (on/off) of equipment such as sensors and limit switches, and converts it into digital signals (0/1) recognizable by the CPU after photoelectric isolation. The analog input module collects continuously changing analog signals such as temperature, pressure, and flow, converts them into digital signals through an A/D converter, and performs filtering and noise reduction to eliminate interference. All collected signals are classified and stored in the data area of the RAM according to the module address, forming a real-time input data image area.
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5. Program Operation Phase: The CPU executes the control program in the RAM line by line in the order of "top to bottom, left to right", and performs operation processing based on the real-time signals in the input data image area. During the operation, multiple types of control logic can be executed: first, basic logical operations, which realize interlocking control of equipment (e.g., judgment of motor start-stop conditions) through logical judgments such as AND, OR, and NOT; second, process control operations, which calculate the deviation between the set value and the collected value through the built-in PID algorithm and output the adjustment amount; third, data processing operations, which perform counting, accumulation, comparison, and other processing on the collected signals (e.g., output statistics, judgment of parameter over-limit). The intermediate data generated by the operation is real-time updated to the intermediate data area of the RAM, and the final operation result is stored in the output data image area.
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7. Command Output Phase: Based on the operation results in the output data image area, the CPU sends control commands to each output module through the backplane bus. The digital output module converts the commands into switch signals to drive the action of executive mechanisms such as relays and contactors (e.g., valve opening/closing, motor start-stop). The analog output module converts the digital commands into analog signals of 4-20mA or 0-10V through a D/A converter to control the operating parameters of equipment such as control valves and frequency converters (e.g., valve opening, motor speed). During the output process, the CPU real-time monitors the execution status of the output module to ensure that the commands are accurately implemented.
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9. Status Feedback and Communication Interaction Phase: After the command is output, the CPU collects the feedback signal of the executive mechanism (e.g., valve opening feedback, motor operating current) through the input module and compares it with the output command. If there is a deviation, it adjusts the next round of output commands through program operation to form closed-loop control. At the same time, the CPU uploads the system operating status (CPU load, input/output signal values, fault information) to the upper-level monitoring system or HMI through the built-in RS232 port or expanded communication module, realizing real-time data monitoring. It receives control parameters (e.g., PID set value, program modification command) issued by the upper-level computer and updates them to the parameter area of the RAM, realizing remote operation and maintenance as well as management and control.

V. Common Faults and Solutions