HW Group HWg-PWR 12, Руководство пользователя

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HWg-PWR 3 / 12 / 25 MANUAL HW group
September 2013 page 39
Meter types
With respect to the mode of operation, meters can be classified as:
- Mains-powered (electricity meters)
- Battery-powered (heat meters, water meters, gas meters etc.)
Manufacturers of battery-powered meters may restrict the number of read operations within
a certain time interval in order to maintain battery life. Typically, one can encounter meters
that allow, for instance, only up to 15 reads/day, 2 reads/hour, etc. These limits differ by
meter type and by manufacturer, and should be specified in the meter documentation.
With the default reading period in HWg-PWR (30s), it is easy to exceed these limits. Then, the
meter stops responding in order to maintain its declared battery life. Exceeding these limits
cannot be considered a defect of HWg-PWR.
Internal memory size
HWg-PWR equipped with 2MB internal memory for storing measured values. The available
recording time depends on the number of values being stored. One value occupies 12 bytes of
memory.
Therefore, 2048kB*1024=2,097,152B/12B = approximately 170,000 records (due to the
internal memory organization, the actual number is slightly smaller).
Examples:
8 values
Recorded once in 5 minutes
170,000/8 = 21,250 records = 1770 hours = 73 days
5 values
Recorded once per 60 s
170,000/5 = 34,000 records = 566 hours = 23 days
25 values
Recorded once per 60 min.
170,000/25 = 6,800 records = 283 days