Chapter 12 Instruction List or a constant. Besides, the operands for an operator are separated by spaces. The operator MOV in the example below denotes that an action of transferring data will be executed. The operands D0 and D1 are the source device and the destination device which take part in the transfer. On an instruction list, the words between (* and *) are regarded as comments. When a program is compiled, the system automatically skips the words between (* and *) . Besides, as long as the structure of an instruction list is not destroyed, comments can be put anywhere on the instruction list. However, users have to be careful about the readability of the instruction list.
The comments in the example below are legal. Instructions are divided into basic instructions and advanced instructions. Please refer to programming manuals for more information about the usage of instructions. If users want to check the usage of an instruction, they can click PLC Instruction and Special Registers Reference on the Help menu. Besides, if users press F1 after they click an instruction, the usage of the instruction will be displayed in the window which appears. 12-3