In the field of industrial automation, programmable logic controllers (PLCs) are the core of control systems. GE Fanuc's Series 90-30 PLC plays an important role in numerous industrial applications due to its modular design, high reliability, and powerful scalability. It allows users to build customized control systems by combining different hardware components according to specific needs. This article aims to provide an in-depth interpretation of the installation and hardware manual for Series 90-30 PLC, systematically elaborating on its system architecture, core component characteristics, installation specifications, and system design points, providing automation engineers with a professional and detailed technical reference.
Part 1: Overview of Series 90-30 PLC System Architecture
The Series 90-30 PLC system adopts a modular and plug-in design, and its basic components include: substrate, power module, CPU module, I/O module, and option module.
Substrate: This is the physical foundation of the PLC system, on which all other modules are installed. The substrate provides electrical connections (backplate) and mechanical fixation between modules. According to their functions, substrates are divided into three categories:
CPU substrate: There must and can only be one in the system, which includes a CPU or provides CPU module slots. The CPU substrate is assigned rack number 0 by default.
Expansion board: Used to add more I/O module slots near the CPU board (up to 50 feet/15 meters cable distance) for faster communication speed.
Remote substrate: used to add I/O module slots at longer distances (up to 700 feet/213 meters), with built-in isolation circuits to accommodate ground potential differences at different locations.
Power module: Each substrate must have a power module installed in its dedicated slot on the far left. The power module provides operating voltage for all other modules on the substrate (+5 VDC,+24 VDC relay power,+24 VDC isolation power).
CPU module: This is the "brain" of PLC, responsible for executing user programs, managing system communication, and conducting self diagnosis. There are multiple models of CPUs with varying performance, memory capacity, and functionality. The CPU can be embedded in the substrate or a standalone module.
I/O modules: These modules are the interfaces between PLC and field devices such as sensors, switches, relays, and solenoid valves. They convert physical signals on site (such as 24VDC, 120VAC) into logic signals that can be processed by PLC, and vice versa. I/O modules are divided into two categories: discrete (switch) and analog.
Option modules: These modules are used to expand the basic functions of PLC, such as implementing network communication (Ethernet, Genius, FIP), motion control (servo positioning), high-speed counting, temperature control, etc.
Part 2: Detailed Explanation of Hardware Components
2.1 Baseplate
The substrate is the skeleton of the system, and its physical size determines the number of modules that can be installed. There are two specifications for Series 90-30 substrates: 5-slot and 10 slot (note that power slots are not counted). The common features of all substrates include:
Module holder: used to secure inserted modules.
Backplane connector: provides power and communication bus connections.
Installation hole: used to fix the substrate to the panel or 19 inch rack.
Rack number selection switch: located on the expansion board and remote board, used to assign a unique rack number (1-7) to each board. The CPU substrate is fixed to rack 0.
Key point: The metal backplate of the substrate must be safely grounded through a separate grounding wire, and installing screws alone is not enough.
2.2 Power Supply Module
The power module provides power to the system. The total output power of all power modules is 30 watts, but their+5VDC output capabilities are different, divided into standard type (15 watts) and high-capacity type (30 watts). The main models include:
IC693PWR321: Standard AC/DC input (100-240VAC or 125VDC).
IC693PWR330: High capacity AC/DC input,+5VDC output up to 30 watts.
IC693PWR322:24/48VDC input.
IC693PWR331:24VDC input high-capacity type.
The key factor in power supply selection is to calculate the total load of all modules to ensure that it does not exceed the rated capacity of the power supply. For example, an IC693CPU351 module consumes 890 mA of+5V current, equivalent to 4.45 watts of power. If multiple high-power modules are installed on a single substrate, it may be necessary to choose a high-capacity power supply.
2.3 CPU module (CPU)
The CPU is the core of the system, and its selection determines the system's processing power, memory capacity, and scalability. CPUs are mainly divided into two categories: embedded (such as 311, 313, 323) and modular (such as 331, 340, 341, 350-374). The manual focuses on introducing the models and features of modular CPUs:
CPU331/340/341: Based on 80C188XL processor, supports up to 5 substrates (1 CPU+4 expansion/remote), with memory ranging from 16K to 80K bytes.