Woodward 8237-1600 505 Digital Governor

Description

5437-1126 Spare Module for 8237-1594, 8237-1598
5437-1127 Spare Module for 8237-1595, 8237-1599
5437-1124 Spare Module for 8237-1596, 8237-1600
5437-1125 Spare Module for 8237-1597, 8237-1601

Programmable controller is an electronic system device with a microprocessor as the core for digital operation, designed specifically for industrial applications. It uses programmable memory to store and execute operational instructions such as logical operations, sequential control, timing/counting, and arithmetic operations internally, and controls various types of mechanical or production processes through digital or analog input and output interfaces. PLC is a product of the combination of microcomputer technology and traditional relay contact control technology. It overcomes the shortcomings of complex wiring, low reliability, high power consumption, poor universality and flexibility of mechanical contacts in relay contact control systems, fully utilizing the advantages of microprocessors, and taking into account the skills and habits of on-site electrical operation and maintenance personnel, especially the programming of PLC, which does not require specialized computer programming language knowledge, Instead, it adopts a simple instruction form based on the relay ladder diagram, making user programming visual, intuitive, and easy to learn; Debugging and error checking are also very convenient. After purchasing the required PLC, users only need to follow the instructions, do a small amount of wiring and simple user programming work, and can flexibly and conveniently apply the PLC to production practice.

There are various types of PLCs, and their functions and instruction systems are also different. However, their structure and working principles are similar, usually consisting of several main components such as the host, input/output interfaces, power extender interfaces, and external device interfaces.

1. Host
The host part includes the central processing unit (CPU), system program memory, and user program and data memory. The CPU is the core of PLC, which is used to run user programs, monitor the status of input/output interfaces, make logical judgments, and perform data processing. It reads input variables, completes various operations specified by user instructions, sends the results to the output end, responds to requests from external devices (such as computers, printers, etc.), and makes various internal judgments. There are two types of internal memory in PLC. One type is system program memory, which mainly stores system management and monitoring programs, as well as programs for compiling and processing user programs. The system programs have been fixed by the manufacturer and cannot be changed by users; The other type is user programs and data storage, which mainly store user generated application programs, various temporary data, and intermediate results.

2. Input/Output (I/O) interface
The I/O interface is a component that connects the PLC to input/output devices. The input interface receives control signals from input devices such as buttons, sensors, contacts, travel switches, etc. The output interface is to drive output devices (such as contactors, solenoid valves, indicator lights, etc.) through the power amplifier circuit based on the processed results of the host. I/O interfaces generally use optoelectronic coupling circuits to reduce electromagnetic interference and improve reliability. The number of I/O points, also known as the number of input/output terminals, is a major technical indicator of PLC. Typically, small machines have dozens of points, medium-sized machines have hundreds of points, and large machines will exceed a thousand points.

3. Power supply
The power supply in the figure refers to a DC switch regulated power supply configured for the operation of internal electronic circuits such as CPU, memory, I/O interface, etc. It usually also provides DC power for input devices.

4. Programming
Programming is the use of external devices by PLC for users to input, check, modify, debug programs, or monitor the operation of the PLC. Connect the PLC to the computer through dedicated PC/PPI cables, and use dedicated software for computer programming and monitoring.

5. Input/output expansion unit
The I/O expansion interface is used to connect the expansion unit that expands the number of external input/output terminals with the basic unit (i.e. the host).

6. External device interface
This interface can connect external devices such as printers, barcode scanners, frequency converters, and the host to complete corresponding operations.
The host model provided for the experimental device is CPU224 (AC/DC/RELAY) from Siemens S7-200 series. The input points are 14 and the output points are 10; CPU226 (AC/DC/RELAY), with 26 input points and 14 output points.