Technical data

Instrument Behavior
Instrument Behavior - Reference
The Serial BERT behaves as follows when it is turned on (or after a power-cycle):
At power on, the Serial BERT will return to the same mode as it was powered down.
Normally, once it has booted, the Serial BERT is ready for either front panel
operation or remote operation.
At power-on, the state of the registers and filters is:
• Normal operation
The initial state of the registers and transition filters will be saved in the event
of a power failure.
• Initial power-on
All registers and filters are disabled except the PON, CME and EXE bits of the
Standard Event Status Register and its summary bit in the Status Byte.
The transition filters will be set to allow all conditions and events to pass.
The event registers and the error queue are cleared at each and every power-up.
Overheat Protection
The Serial BERT protects itself from damage by overheating by shutting itself down
in such cases.
If the temperature of the pattern generator or error detector generator exceeds a
certain threshold, the OVERHEAT bit in the Operation register is set.
There are two thresholds: caution and warning. These both set the same bit: you
cannot programmatically get the threshold.
The caution threshold is not critical. You have enough time to save your current
settings and gracefully shut down the instrument.
The warning threshold is critical. If this threshold is reached, the instrument will
immediately shut itself down.
Overtemperature can be programmatically detected by querying the Status byte
(*STB). In case of overheating by either the error detector or pattern generator, the
Operation bit (bit 7) in the Status byte will be high, as will the OVERHEAT bit in the
Operation register. See “How the Serial BERT Uses Status Registers” on page
25 for details on reading the status registers.
1 Programming Basics
10 Agilent J-BERT N4903B High-Performance Serial BERT
Instrument Mode
Registers and Filters