User manual OMRON CPM2A PROGRAMING MANUAL 02-2001

[. . . ] W353-E1-06 SYSMAC CPM1/CPM1A/CPM2A/CPM2C/SRM1(-V2) Programmable Controllers PROGRAMMING MANUAL CPM1/CPM1A/CPM2A/CPM2C/SRM1(-V2) Programmable Controllers Programming Manual Revised February 2008 iv Notice: OMRON products are manufactured for use according to proper procedures by a qualified operator and only for the purposes described in this manual. The following conventions are used to indicate and classify precautions in this manual. Failure to heed precautions can result in injury to people or damage to property. ! DANGER Indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury. ! [. . . ] AND instructions in series can be considered individually, with each taking the logical AND of the execution condition (i. e. , the total of all conditions up to that point) and the status of the AND instruction's operand bit. If both of these are ON, an ON execution condition will be produced for the next instruction. The execution condition for the first AND instruction in a series is the first condition on the instruction line. Each AND NOT instruction in a series would take the logical AND between its execution condition and the inverse of its operand bit. 338 Basic Ladder Diagrams OR and OR NOT Section 6-3 When two or more conditions lie on separate instruction lines running in parallel and then joining together, the first condition corresponds to a LOAD or LOAD NOT instruction; the rest of the conditions correspond to OR or OR NOT instructions. The following example shows three conditions which correspond in order from the top to a LOAD NOT, an OR NOT, and an OR instruction. Again, each of these instructions requires one line of mnemonic code. 00000 Instruction 00100 LR 0000 Address 00000 00001 00002 00003 Instruction LD NOT OR NOT OR Instruction Operands 00000 00100 0000 LR The instruction would have an ON execution condition when any one of the three conditions was ON, i. e. , when IR 00000 was OFF, when IR 00100 was OFF, or when LR 0000 was ON. OR and OR NOT instructions can be considered individually, each taking the logical OR between its execution condition and the status of the OR instruction's operand bit. If either one of these were ON, an ON execution condition would be produced for the next instruction. Combining AND and OR Instructions When AND and OR instructions are combined in more complicated diagrams, they can sometimes be considered individually, with each instruction performing a logic operation on the execution condition and the status of the operand bit. Study this example until you are convinced that the mnemonic code follows the same logic flow as the ladder diagram. 00000 00001 00002 00003 Instruction 00200 Address 00000 00001 00002 00003 00004 00005 Instruction LD AND OR AND AND NOT Instruction Operands 00000 00001 00200 00002 00003 Here, an AND is taken between the status of IR 00000 and that of IR 00001 to determine the execution condition for an OR with the status of IR 00200. The result of this operation determines the execution condition for an AND with the status of IR 00002, which in turn determines the execution condition for an AND with the inverse (i. e. , and AND NOT) of the status of IR 00003. 339 Basic Ladder Diagrams Section 6-3 In more complicated diagrams, however, it is necessary to consider logic blocks before an execution condition can be determined for the final instruction, and that's where AND LOAD and OR LOAD instructions are used. Before we consider more complicated diagrams, however, we'll look at the instructions required to complete a simple "input-output" program. 6-3-4 OUTPUT and OUTPUT NOT The simplest way to output the results of combining execution conditions is to output it directly with the OUTPUT and OUTPUT NOT. These instructions are used to control the status of the designated operand bit according to the execution condition. With the OUTPUT instruction, the operand bit will be turned ON as long as the execution condition is ON and will be turned OFF as long as the execution condition is OFF. With the OUTPUT NOT instruction, the operand bit will be turned ON as long as the execution condition is OFF and turned OFF as long as the execution condition is ON. In mnemonic code, each of these instructions requires one line. 00000 01000 Address 00000 00001 Address 00000 00001 Instruction LD OUT Instruction LD OUT NOT Operands 00000 01000 Operands 00001 01001 00001 01001 In the above examples, IR 01000 will be ON as long as IR 00000 is ON and IR 01001 will be OFF as long as IR 00001 is ON. Here, IR 00000 and IR 00001 would be input bits and IR 01000 and IR 01001 output bits assigned to the Units controlled by the PC, i. e. , the signals coming in through the input points assigned IR 00000 and IR 00001 are controlling the output points assigned IR 01000 and IR 01001, respectively. The length of time that a bit is ON or OFF can be controlled by combining the OUTPUT or OUTPUT NOT instruction with Timer instructions. Refer to Examples under 7-15-1 Timer ­ TIM for details. 340 Basic Ladder Diagrams Section 6-3 6-3-5 The END Instruction The last instruction required to complete a simple program is the END instruction. When the CPU Unit scans the program, it executes all instructions up to the first END instruction before returning to the beginning of the program and beginning execution again. Although an END instruction can be placed at any point in a program, which is sometimes done when debugging, no instructions past the first END instruction will be executed until it is removed. The number following the END instruction in the mnemonic code is its function code, which is used when inputted most instruction into the PC. [. . . ] W353-E1-06 Revision code The following table outlines the changes made to the manual during each revision. Page numbers refer to the previous version. Revision code 1 2 Date May 1999 January 2000 Original production Revised content Information on new Expansion Units and the relevant PCs was added throughout the manual. Additional changes were made on the following pages: Page xi: Updated to new contents of manual. Page xvii: Ground precaution changed to warning and moved to safety precaution section. [. . . ]