Acumen SDR2-USB manual Stopping recording, Device removal while recording, Filename generation

Operations SDR2-USB Configuration Guide rev 1.0

3.2.2Stopping recording

Incoming data is written to the open file as it is received until you stop recording by pressing the record button. The SDR2-USB then closes the file, updates its directory entry (recording file size, date, and time), and returns to stop mode.

3.2.3Device removal while recording

Do not terminate recording by removing the USB storage device without stopping the recorder, or disk corruption may occur.

3.2.4Power failure and improper shutdowns

If the SDR2-USB loses power while in record mode, it returns to record mode after power is restored.

An improper shutdown may result in loss of data (due to sector buffering and caching in the storage device) and minor allocation errors that can be repaired using the Windows 95/98/NT/2000/XP/Vista™ Explorer or chkdsk.exe from the Windows Command Prompt.

3.2.5Filename generation

When operating with Append=0 (see section 4.1.3), unique new filenames are generated based on the specified filename. This is done to avoid overwriting an existing file within the specified folder.

Filenames are generated by “incrementing”. Before incrementing, the file’s name is extended to 8 characters with a sequence of zeros. From there, the filename’s last character is incremented through the digits 0-9 and A-Z, carrying to the next-last as needed. An example of incrementing is shown in Figure 3.1.

Before Incrementing	After Incrementing
BRIDGE.DAT	BRIDGE01.DAT
BRIDGE01.DAT	BRIDGE02.DAT
BRIDGE09.DAT	BRIDGE0A.DAT
BRIDGE0Z.DAT	BRIDGE10.DAT
BRIDGE10.DAT	BRIDGE11.DAT

Figure 3.1. Generating filenames when append mode is off.

3.2.6Full storage media

When the storage media’s first valid partition is full, the SDR2-USB returns to stop mode unless overwrite-oldest mode is enabled, in which case the SDR2-USB will delete the oldest file in the target folder and return to recording mode.

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