Omron CPM1A operation manual Flash Memory Precautions

Initial System Checks and Test Run Procedure Section 5-1

5-1-3 Flash Memory Precautions

Observe the following precautions to protect the flash memory and ensure proper operation.

1, 2, 3... 1. If the power is turned off without changing the mode after having made chan- ges in the read-only DM area (DM 6144 through DM 6599), or PC Setup (DM 6600 through DM 6655), the contents of changes will not be written to flash memory. Therefore, if the power is turned off for more than 20 days (at 25_C), contents of changes (contents of the RAM) will disappear and the data values will become undefined values. For details, refer to 2-1-2 Char- acteristics.

The changes can be saved by switching the CPM1A to RUN or MONITOR mode or turning on the CPM1A soon after the changes are made.

2.When the CPM1A is operated for the first time after changing the program, the read-only DM area (DM 6144 through DM 6599) or PC Setup (DM 6600 through DM 6655) will take about 600 ms longer than usual. Be sure to take this one-time startup delay into account.

3.If one of the following three operations is performed in MONITOR or RUN mode, the CPM1A will extend the cycle time for up to 600 ms and interrupts will be disabled while the program or PC Setup is being overwritten.

•Program changes with the online edit operation

•Changes to the read-only DM area (DM 6144 through DM 6599)

•Changes to the PC Setup (DM 6600 through DM 6655)

A “SCAN TIME OVER” error won’t occur during these operations. The CPM1A’s I/O response times may be affected when the online edit operation is being performed.

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