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Appendix | Digital Interface RS485
ACC5703
A new sampled measurement value is saved to the internal buffer of the sensor. The maximum number of
values which can be saved is 19 for each measurement axis. Therefore, an enquiry by the master must reach
the sensor within a certain time, that depends on the set sampling rate, in order to read the content from the
internal memory and ensure uninterrupted sampling (periodic enquiry).
- Example 1 kHz: 19 values * 1 ms = 19 ms
- Example 250 Hz: 19 values * 4 ms = 76 ms
If the enquiries are not made in time, error flag 0x01 is set in the status byte. The measurement is continued
anytime, i.e. the values in the buffer which are not read will be overwritten with updated measurements. The
buffer content is, therefore, always updated. The overflow error flag is deleted automatically as soon as the
master resumes its periodic enquiries.
The analog output remains unaffected by this. The first measurement value in the Data[] package is the old-
est measured value. A measured value is represented as 4-byte float data type in the unit [g]
1
.
1) 1 g = 9.81 m
s
2