powerpoint ® presentation chapter 5 plc programming instructions plc programming diagrams processor...
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PowerPoint® Presentation
Chapter 5PLC Programming Instructions
Chapter 5PLC Programming Instructions
PLC Programming Diagrams • Processor Files • Program Files • Data Table Files • Data Table File
Addresses • Input and Output File Addresses • Status File Addresses • Bit File Addresses • Programming Diagram Logic • Programming
Diagram Rules • Bit Instructions • Scan Execution
Chapter 5 — PLC Programming Instructions
A hardwired motor control application is depicted by symbols in a ladder diagram.
Chapter 5 — PLC Programming Instructions
A PLC motor control application is depicted by instructions in a programming diagram.
Chapter 5 — PLC Programming Instructions
The memory of a PLC contains the processor file, which contains the program files and data table files.
Chapter 5 — PLC Programming Instructions
There are 256 possible program files, with the function of program files 0, 1, and 2 defaulted by the PLC.
Chapter 5 — PLC Programming Instructions
The status of the CPU, all input devices and output components, and all instructions used in the program are found in the 256 data table files.
Chapter 5 — PLC Programming Instructions
The instructions within each data table file each have a unique address based on the file identifier and file number.
Chapter 5 — PLC Programming Instructions
Input and output terminals are addressed as slot.word/bit or slot/bit. Standard I/O modules have 16 points (terminals) and require 1 word of memory. High-density modules have 32 points and require 2 words of memory.
Chapter 5 — PLC Programming Instructions
Information in status files is formatted as word/bit or as a word. The addressing format depends on the contents of the status file.
Chapter 5 — PLC Programming Instructions
The default bit file is B3. Bit file addresses are formatted as word/bit, bit, or as a word.
Chapter 5 — PLC Programming Instructions
A PLC or programming software will not accept a program when the program does not follow standard rules.
Chapter 5 — PLC Programming Instructions
Ladder diagrams depict the flow of current through hardwired devices and components, while PLC program diagrams depict the flow of logic through instructions.
Chapter 5 — PLC Programming Instructions
The type of input instruction, XIC or XIO, determines how the rung of a program will operate with a normally open (NO) input device.
Chapter 5 — PLC Programming Instructions
The type of input instruction, XIC or XIO, determines how the rung of a program will operate with a normally closed (NC) input device.
Chapter 5 — PLC Programming Instructions
The XIC holding contact uses the same address as an OTE instruction but is not a hardwired contact and only exists in the memory of a PLC.
Chapter 5 — PLC Programming Instructions
OTL (latch) instructions can only turn a bit ON, and OTU (unlatch) instructions can only turn a bit OFF.
Chapter 5 — PLC Programming Instructions
PLCs scan program diagrams in a specific manner, with the placement of instructions impacting scan times.