Operating instructions
OPTIMOD-AM DIGITAL MAINTENANCE
4-11
B) Be sure you are still in BYPASS mode [see step (3.F)].
C) Navigate to S
ETUP > DIG IN CALIB and Set the INPUT to DIGITAL.
D) Connect the digital source generator to the AES3 Digital Input XLR connector
of the 9400.
E) Set the frequency of the digital source generator to 400 Hz and its output
level to 6 dB below full scale.
F) Inject the Digital Input with a sample rate of 32 kHz, 44.1 kHz, 48 kHz, 88.2
kHz, and 96 kHz. Use 24-bit words.
G) Listen to the analog outputs of the 9400 and verify that the output sounds
clean and glitch-free regardless of the input sample rate.
H) Leave the digital source generator connected to the 9400.
7. Test Digital Sample Rate Converter (Transmitter).
A) Connect an AES3 analyzer (like the Audio Precision System 2) to the 9400’s
AES3 Digital Output #1.
B) Set the sample rate of the digital source generator to 48 kHz.
C) Navigate to S
ETUP > DIG OUT CALIB.
D) Change the D
O RATE to 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, and 96 kHz, and
verify that the frequencies measured at the 9400’s AES3 output follow the
values in the chart below within given tolerances:
Sample Rate Tolerance (PPM) Tolerance ( Hz)
32.0 kHz 100 PPM ±1.60 Hz
44.1 kHz 100 PPM ±4.41 Hz
48.0 kHz 100 PPM ±2.40 Hz
88.2 kHz 100 PPM ±8.82 Hz
96.0 kHz 100 PPM ±4.80 Hz
E) Repeat steps (A) through (D) for Digital Output #2.
F) Disconnect the digital source generator from the 9400.
8. Optional tests.
A) You can test each GPI (Remote Interface) input for functionality in the obvi-
ous way, by programming a function for it and then verifying that the func-
tion executes when you activate the input. To program a GPI input, see
Remote Control Interface Programming on page 2-46.
B) You can test the RS-232 Port 1 for functionality by verifying
that you can con-
nect to a PC through a null modem cable. See Networking and Remote Con-
trol starting on page 2-47 (in particular, step 4 on page 2-49).
C) You
have made all of the previous tests with the 9400 is B
YPASS mode. In most
cases, these tests are sufficient to determine that the 9400 is working cor-
rectly. However, the B
YPASS mode does not use all of the DSP chips, so the