Chapter 6 Applied Instruction API 1804 Symbol: S ： Unit address Word D ： Initial device in which the data is stored Word Explanation: 1. The operand S should be within the range between 1 and 255. It can not be 0. 2. D : The data which the PLC receives from the AC motor drives is stored in the device specified by users. 3. The instruction is used to read the states of the devices at the addresses 16#2100~16#2104 in the AC motor drive. (Please refer to AC Motor Drive User Manual for more information about the states of the devices.) The data which is received is stored in the device specified by D .
However, the data in D can not be altered if the communication timeout occurs or an error occurs during the reception of the data. Therefore, make sure of the setting of SM100/SM101 before the PLC reads the states of the devices in the AC motor drive. 4. The operand D occupies five registers, i.e. D n , D n +1, D n +2, D n +3, and D n +4. Example: 1. The PLC is connected to the VFD series AC motor drive (ASCII mode: SM210 and SM212 are OFF). If the communication timeout occurs, the PLC retries the sending of the command. 2. The PLC reads the states of the devices at the addresses 16#2100~16#2104 in the AC motor drive. The data which is received is stored in D100~D104.
6-405 Instruction code Operand Function RDST S, D Reading the statuses of the AC motor drives Device X Y M S T C HC D L SM SR E PR K 16# “$” DF S D Pulse instruction 16-bit instruction (5 steps) 32-bit instruction - AH500 -