NTi Audio Digirator DR2 - Manual (Page 46)

Measuring Functions
46
I/O Delay test (Latency)
The function I/O Delay (latency) test determines the exact time
delay which a piece of equipment or an entire system is intro-
ducing. For this test, the SYNC input connector of the DR2 is
used for receiving the delayed signal.
1
2
3
Function
DR2 generates a short test burst every 2 seconds. The SYNC
input is continuously monitored and the delay calculated. Level
adjustments and minor distortion do not affect the measure-
ment result.
Sampling frequency, synchronization and clock source
The sampling frequency can be selected to be either 32, 44.1
or 48 kHz. These frequencies can also be used for external syn-
chronization, provided the accuracy is within ±100 ppm.
The sampling frequency of the input signal may be non-syn-
chronized and range anywhere from 20 - 216 kHz.
Right after the connection of a signal to the SYNC input, the
DR2 queries for the desired termination impedance and after
that whether the clock should be generated internally or syn-
chronized to the external source.
Also refer to the synchronization details outlined in the section
„Channel transparency testing“.
Test sequence
For measuring the I/O delay (latency) of a device, please pro-
ceed as follows:
1. Connect the output of the DR2 with the input of the device
under test.
2. Connect the AES3 output of the device with the SYNC in-
put of the DR2.
3. Make the proper settings for termination impedance and
clock source.

The result of the I/O delay (latency) measurement is now
continuously displayed.