Woodward 8273-140 2301D Digital Load Sharing Module

Description

The 2301E controller is backward compatible with existing 2301D products, since it has the same footprint and mounting configuration.

PLC operates in a “sequential scanning, continuous cycling” manner. When the PLC is running, the CPU compiles a program that coexists in the user’s memory according to the user’s control requirements, and performs periodic cyclic scanning according to the instruction step number (or address number). If there are no jump instructions, the user program is executed sequentially from the first instruction until the program ends. Then return to the first instruction and start the next round of scanning. During each scanning process, it is also necessary to complete tasks such as sampling the input signal and refreshing the output status.

A scanning cycle of PLC must go through three stages: input sampling, program execution, and output refresh.
In the input sampling stage of PLC, the on/off status or input data of all input terminals temporarily stored in the input latch are first read in sequence through scanning, and written to the corresponding input status registers to refresh the input. Immediately close the input port and enter the program execution phase.

During the program execution phase, PLC scans and executes each instruction in the order in which the user program instructions are stored. After corresponding calculations and processing, the results are written to the output status register, and all contents in the output status register change with the execution of the program.
Output refresh stage: When all instructions are executed, the on/off status of the output status register is sent to the output latch during the output refresh stage, and is output through a certain method (relay, transistor, or thyristor) to drive the corresponding output device to work.

1. Programming elements
PLC uses software programming to achieve control requirements. When programming, various programming components need to be used, which can provide countless dynamic closing and dynamic breaking contacts. Programming components refer to input registers, output registers, bit memory, timers, counters, general registers, data registers, and special function memory.
The function of these memories inside the PLC is very similar to the relays used in relay contact control systems, with “coils” and “contacts”, but they are not “hard” relays, but rather storage units of the PLC memory. When the logical state written to the unit is “1”, it indicates that the corresponding relay coil is powered on, its dynamic closing contact is closed, and the dynamic breaking contact is open. So, these internal relays are called “soft” relays.

2. Programming Language
The so-called programming refers to the process in which users describe a control requirement based on the requirements of the control object using the programming language provided by the PLC manufacturer. The most commonly used programming languages for PLC are ladder diagram language and instruction statement table language, and the two are often used in combination.
1) Ladder diagram (language)
Ladder diagram is a graphical language that evolved from relay contact control circuit diagrams. It is a graphical representation of the logical relationship between PLC input and output, which is connected according to control requirements using terms and symbols such as dynamic closing, dynamic breaking contacts, coils, and series and parallel connections, similar to relays. It is intuitive and easy to understand.
The commonly used graphical symbols in the ladder diagram represent the dynamic closing and dynamic breaking contacts of PLC programming components;
Use () to represent their coils. The types of programming components in a ladder diagram are distinguished by graphical symbols and labeled letters or numbers. The independent circuit composed of contacts and coils is called a network. The ladder diagram and statement table program generated by programming software have network numbers, allowing annotations to be added to the ladder diagram on a network basis.

MSK101E-0300-NN-M1-BG2-NNNN
MSK061C-0600-NN-S1-UGO-NNNN
MSK050C-0300-NN-M1-UG1-NNNN
MSK101D-0300-NN-M1-BG2-NNNN
MSK101C-0300-NN-M1-BG2-NNNN
MHD071B-061-NG0-UN
MSKO70C-0150-NN-M1-UG0-NNNN
MSKO50B-0300-NN-M1-UG1-NNNN
MSK040B-0450-NN-M1-UG0-NNNN
DDS02.1-A200-D
DDS02.1-W050-D
DDS02.1-W100-02-FWA
DDS02.1-W100-DL01-01-FW
DDS02.1-W100-DS46-00-FW
DDS02.1-W150-D
DDS02.1-W150-DS01-02-FW
DDS02.1-W150-DS04-03-FW
DDS02.1-W200-D
DDS02.2-A100-B
DDS02.2-A100-BE45-01-FW
MSK101D-0300-NN-M1-BG3-NNNN
MSK101D-0300-NN-S1-AGO-NNNN
MSK101D-0300-NN-S1-BG0-NNNN