Commissioning
7.9 Notes on operation
SIMATIC HMI IPC677C
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Operating Instructions, 04/2013, A5E02722710-04
Comparison of Flash drive and hard disk drive service life
Examples of the service life for a Flash drive
With a "Data logger function", a 4 KB file is written to a 1 GB Compact Flash card every
5 seconds. The cluster size is 4 KB in this case. Due to the file segmentation, the file is
always written to another location on the Compact Flash card.
With this example, the Compact Flash card has a theoretical service life of 79.3 years.
Example of the service life for a hard disk drive
The service life of a hard disk drive depends on the following factors:
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Temperature (operating & storage / transport)
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Shock (operating & storage / transport)
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Vibration (operating & storage / transport)
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Humidity (operating & storage / transport)
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Voltage supply
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Power on hours (POH)
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Duty cycle (% workload, i.e. write/read/positioning)
The service life for a hard disk is between 2.5 and 5 years, depending on the factors listed
above.
Booting from the Flash drive
A operating system must be installed before you can boot from the Flash drive. You can read
about the procedure required for installation of an operating system in the section Installing