Grace m908 - Error Messages

m908 User Manual, Rev. G
If the clock output parameter is set for <system clock> and the m908 is being synchronized to
an external word clock, the Word Clock output will be a re-clocked low jitter version of the
incoming clock. If the incoming clock is interrupted the m908 will continue to transmit on the
Word Clock output at the last frequency that the system was locked to. When the input clock is
restored the m908 will re-lock smoothly unless then new incoming sample rate has changed.
See Word Clock Termination Setup and Word Clock Output Setup for setup instructions.
The word clock polarity is high for left channel data and low for right channel data.
5.23 Error Messages
The ACU monitors several hardware systems for fault conditions and will report errors if there
are any detected faults.
5.23.1 ACU Over Temperature
The ACU contains a temperature sensor on the circuit board near the main DSP processor. If
the temperature rises above a safe level for the processor then the RCU will report an over
temperature condition.
If this message appears check that the ACU has proper ventilation and that the ambient
temperature where it is installed is below 40°C (104°F). Verify that the fan exhaust on the right
side of the chassis and the cool air inlet openings on the left side of the chassis are not obstructed.
Page 50 of 135 Table Of Contents
Illustration 29: Word Clock Flow Diagram
WC IN
WC OUT
75Ω
CLOCK TERM CLOCK OUT
s-LOCK
PLL