Record timestamps Sample Clauses

Record timestamps. AlazarTech digitizer boards include a 40-bit counter clocked by the sample clock source scaled by a board specific divider. When a board receives a trigger event to capture a record to on-board memory, it latches and saves the value of this counter. The counter value gives the time, relative to when the counter was reset, when the trigger event for the record occurred. By default, this counter is reset to zero at the start of each acquisition. Use AlazarResetTimeStamp to control when the record timestamp counter is reset. Use AlazarGetTriggerAddress to retrieve the timestamp, in timestamp clock ticks, of a record acquired to on-board memory. This function does not convert the timestamp value to seconds. The following code fragment gets the record timestamp of a record acquired to on-board memory, and converts the timestamp value from clocks ticks to seconds. // Read the record timestamp U32 triggerAddress; U32 timestampHigh; U32 timestampLow; AlazarGetTriggerAddress ( boardHandle, // HANDLE -- board handle record, // U32 -- record number (1-indexed) &triggerAddress, // U32* -- trigger address &timestampHigh, // U32* -- timestamp high part &timestampLow // U32* -- timestamp low part ); // Convert the record timestamp from counts to seconds timeStamp_cnt = (( int64) timestampHigh) << 8; timeStamp_cnt |= timestampLow & 0x0ff; double samplesPerTimestampCount = 2; // board specific constant double samplesPerSec = 50.e6; // sample rate double timeStamp_sec = (double) samplesPerTimestampCount * timeStamp_cnt / samplesPerSec; Call AlazarGetParameter with the GET_SAMPLES_PER_TIMESTAMP_CLOCK parameter to obtain the board specific “samples per timestamp count” value. The following table lists these values. Model Samples per timestamp count ATS310, ATS330, ATS460, ATS660, ATS9462, ATS9870, ATS9350 2 ATS850, ATS860 4 See “%ATS_SDK_DIR%\Samples\SinglePort\AR_Timestamps” for a complete sample program that demonstrates how to retrieve record timestamps and convert them to seconds.

Record timestamps. AlazarTech digitizer boards include a high-speed 40-bit counter that is clocked by the sample clock source scaled by a board specific divider. When a board receives a trigger event to capture a record to on-board memory, it latches the value of this counter. This timestamp value gives the time, relative to when the counter was reset, when the trigger event for this record occurred. By default, this counter is reset to zero at the start of each acquisition. Use AlazarResetTimeStamp to control when the record timestamp counter is reset. The following code fragment demonstrates how to extract the timestamp from a record header, and covert the value from counts to seconds. double samplesPerTimestampCount = 2; // board specific constant double samplesPerSec = 100.e6; // sample rate void* xXxxxxx; // points to record header in buffer ALAZAR_HEADER *pHeader = (ALAZAR_HEADER*) xXxxxxx; timestamp_counts = (INT64) pHeader->hdr2.TimeStampLowPart; timestamp_counts = timestamp_counts | ((( int64) (pHeader->hdr3.TimeStampHighPart & 0x0ff)) << 32); double timestamp_sec = samplesPerTimestampCount * timestamp_counts / samplesPerSec; Call AlazarGetParameter with the GET_SAMPLES_PER_TIMESTAMP_CLOCK parameter to determine the board specific “samples per timestamp count” value. The following table lists these values. Model Samples per timestamp count ATS310, ATS330, ATS460, ATS660, ATS9462, ATS9870, ATS9350 2 ATS850, ATS860 4 See “%ATS_SDK_DIR%\Samples\DualPort\TR_Header” for a full sample program that demonstrates how to make an AutoDMA acquisition in Traditional mode with record headers, and convert the timestamp to seconds.