2 Functions of Devices in DVP-PLC (5) When the program is copied, the MPU automatically copies the password function (including the main password, the limit on the number of errors, the subroutine password, and the PLC ID). Function Group Reading/Writing the data from/into the backup area Number M1164, D1064 Contents: 1. The function of reading/writing data from/into the backup area in a PLC can be used only when the PLC stops. 2. The reading/writing of the data between the EH2 series MPU and the backup area: Note: (1) After the reading/writing of the data is complete, M1164 is automatically set to Off. After the reading/writing of the data is complete, the following flags are On.
M1189 The data which is read/written is correct. M1075 An error occurs when the data is written into the backup area. Before replacing the PLC, please read the program and the data form the main operation area first. (2) Enter the function code in D1064 first, and then set M1164 to On. Otherwise, M1164 is automatically reset to Off. (3) If an error occurs during the reading/writing of the data, the special M will be set. No error LED indicator will flash or no situation in which the MPU can not run occurs. Therefore, if customers need an alarm, please make the warning message on the device or superior machine according to the flags above.
(4) Owing to the fact that the storage material of the backup area is Flash ROM, it takes some execution time to write the data into the memory card. (5) When the program is copied, the MPU automatically copies the password function (including the main password, the limit on the number of errors, the subroutine password, and the PLC ID). 3. The reading/writing of the data between the EH3/SV2 series MPU and the backup area: DVP-PLC Application Manual 2-88 M1164 state D1064 code Function On 0x55AA The program and the data in D2000~D9999 are read from the backup area, and copied to the main operation area.
0xAA55 The program and the data in D2000~D9999 in the main operation area are copied to the backup area. M1164 state D1064 code Function On 0x55AA The program and the data in D2000~D9999 are read from the backup area, and copied to the main operation area. 0x55A9 The program is read from the backup area, and copied to the main operation area in the MPU. 0x55AB The data is read from D2000~D11999 in the backup area, and copied to the main operation area in the MPU. 0xAA55 The program and the data in D2000~D9999 in the main operation area are copied to the backup area. 0xA955 The program in the main operation area is copied to the backup area.