Chapter 5 Basic Instructions 5.2 Basic Instructions Symbol: LD S ： Specified device Bit AND OR Explanation: 1. The instruction LD applies to contact A which starts from the mother line or contact A which is the start of a contact circuit. It functions to reserve the current contents, and store the contact state which is acquired in the accumulative register. 2. The instruction AND is used to connect contact A in series. It functions to read the state of the contact which is specified to be connected in series, and perform the AND operation with the previous logical operation result. The final result is stored in the accumulative register. 3.
The instruction OR is used to connect contact A in parallel. It functions to read the state of the contact which is specified to be connected in parallel, and perform the OR operation with the previous logical operation result. The final result is stored in the accumulative register. Example: 1. Contact A of X0.0 is loaded, contact A of X0.1 is connected in series, contact A of X0.2 is connected in parallel, and the coil Y0.0 is driven. 2. When both X0.0 and X0.1 are ON, or when X0.2 is ON, Y0.0 is ON.
5-3 Instruction code Operand Function LD/AND/OR S Loading contact A/Connecting contact A in series/Connecting contact A in parallel Device DX DY X Y M SM S T C HC D L PR S ● ● ● ● ● ● ● ● ● ● ● ●