Spectrum Brands MC.31XX 用户手册

Option Timestamp

General information

(c) Spectrum GmbH

83

The timestamp function is used to record trigger events relative to the beginning of the measurement, relative to a fixed time-zero point or 
synchronized to an external radio clock. This is done by a wide resetable counter that is incremented with every sample rate. With every 
detected trigger event the actual counter value is stored in a seperate timestamp memory.

This function is designed as an enhancement to the Multiple Recording and the Gated Sampling mode but can also be used without these 
options. If Gated Sampling mode is used, then both the start and end of a recorded segment are timestamped.

The timestamp memory is designed as a FIFO buffer so that it can be read out even while the Spectrum board is recording data continuously 
to the PC in the FIFO mode. This extra memory is 64 K Timestamps in size.

Each recorded timestamp consists of the number of samples that has been counted since the last 
counter reset has been done. The actual time from the point since the last reset has been done so 
can easily be calculated by the formular besides.

If you want to know the time between two timestamps, you can simply calculate this by the for-
mular besides.

The timestamp counter is running with the sampling clock on the base card. Some card types (like 2030 and 3025) use an interlace mode 
to double the sampling speed. In this case the timestamp counter is only running with the non-interlaced sampling rate. Therefore the maximum 
counting frequency of the timestamp option is limited to 125 MS/s.

In standard mode the timestamp counter is set to zero 
once by writing the TS_RESET commando to the com-
mand register. After that command the counter counts 
continuously.
The timestamps of all recorded trigger events are refer-
enced to this common zero time. With this mode you 
can calculate the exact time difference between differ-
ent recordings.
The following table shows the valid values that can be 
written to the timestamp command register.

In StartReset mode the timestamp counter is set to zero 
on every start of the board. After starting the board the 
counter counts continuously.
The timestamps of one recording are referenced to the 
start of the recording. This mode is very useful for Multi-
ple Recording and Gated Sampling (see according 
chapters for detailed information on these two optional 
modes).
The following table shows the valid values that can be 
written to the timestamp command register.

SPC_TIMESTAMP_CMD

47000

w

Writes a command to the timestamp command register.

SPC_TIMESTAMP_CMD

47000

r

Reads out the actual timestamp mode.

TS_RESET

0

Resets the counter of the timestamp module to zero.

TS_MODE_DISABLE

10

Disables the timestamp module. No timestamps are recorded.

TS_MODE_STANDARD

12

Must be written to enable the Standard timestamp mode. The counter must be manually reset by writing the command 
TS_RESET to the command register. The timestamps values will be relative to this reset time.

SPC_TIMESTAMP_CMD

47000

w

Writes a command to the timestamp command register.

SPC_TIMESTAMP_CMD

47000

r

Reads out the actual timestamp mode.

TS_RESET

0

Resets the counter of the timestamp module to zero.

TS_MODE_DISABLE

10

Disables the timestamp module. No timestamps are recorded.

Timestamp

Sample rate

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∆

Timestampn 1

+

Timestampn

–

Sample rate

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