Introduction to PLC basic instructions
Programmable controller, called Programmable Controller in English.It is a microprocessor-based digital computing operation electronic system device designed for industrial field applications. It uses programmable memory to perform logic operations, sequence control, timing/in its internal memory. Operational instructions such as counting and arithmetic operations, and control various types of mechanical or production processes through digital or analog input and output interfaces.
1.the standard contact instructions
The LD moving contact command indicates a moving contact command connected to the input bus, that is, the logical operation start of the moving contact.
The LDN break contact command indicates a break contact command connected to the input bus, that is, the start of the logical operation of the break contact.
A and dynamic contact command for series connection of single moving contacts. AX and non-break contact command for series connection of single break contacts.
O or moving contact command for parallel connection of individual moving contacts. ON or non-break contact command for parallel connection of individual break contacts.
The data type of the variable in the LD, LDN, A, AN, O, and ON contact instructions is Boolean (BOOC) type. Two commands, LD and LDN, are used to connect the contacts to the bus. The A, AN, O, and ON commands can be used repeatedly. However, when two or more contacts are connected in series to connect the circuit blocks in parallel, The OLD instruction described.
2.the parallel connection block of the circuit block --- OLD
A circuit in which two or more contacts are connected in series is called a series circuit block. When the series circuit is connected in parallel, the LD.LDN instruction is used at the beginning, and the OLD instruction is used at the end of the branch. Both the OLD instruction and the ALD instruction described below have no target component instruction, and the steps of the two non-target component instructions are one step. OLD is sometimes referred to simply as a block instruction.
3. Series Connection Instruction ALD of Parallel Circuit
Two or more junction parallel circuits are called parallel circuit blocks. When the branch circuit parallel circuit blocks are connected in series with the front circuit, the ALD instruction is used.The starting point of the branch is LD and LDN instructions. After the parallel circuit is finished, ALD instructions are used in series with the front circuit. ALD instruction is also referred to as block instruction. ALD is also a step-by-step instruction without operating target components.
1.the standard contact instructions
The LD moving contact command indicates a moving contact command connected to the input bus, that is, the logical operation start of the moving contact.
The LDN break contact command indicates a break contact command connected to the input bus, that is, the start of the logical operation of the break contact.
A and dynamic contact command for series connection of single moving contacts. AX and non-break contact command for series connection of single break contacts.
O or moving contact command for parallel connection of individual moving contacts. ON or non-break contact command for parallel connection of individual break contacts.
The data type of the variable in the LD, LDN, A, AN, O, and ON contact instructions is Boolean (BOOC) type. Two commands, LD and LDN, are used to connect the contacts to the bus. The A, AN, O, and ON commands can be used repeatedly. However, when two or more contacts are connected in series to connect the circuit blocks in parallel, The OLD instruction described.
2.the parallel connection block of the circuit block --- OLD
A circuit in which two or more contacts are connected in series is called a series circuit block. When the series circuit is connected in parallel, the LD.LDN instruction is used at the beginning, and the OLD instruction is used at the end of the branch. Both the OLD instruction and the ALD instruction described below have no target component instruction, and the steps of the two non-target component instructions are one step. OLD is sometimes referred to simply as a block instruction.
3. Series Connection Instruction ALD of Parallel Circuit
Two or more junction parallel circuits are called parallel circuit blocks. When the branch circuit parallel circuit blocks are connected in series with the front circuit, the ALD instruction is used.The starting point of the branch is LD and LDN instructions. After the parallel circuit is finished, ALD instructions are used in series with the front circuit. ALD instruction is also referred to as block instruction. ALD is also a step-by-step instruction without operating target components.
