Table of Contents
Advertisement
7.6 A
S
MPLIFIER
HUTDOWN
Each unit shuts down due to an alarm or as a result of a hardware or software command.
A software shutdown is achieved by selecting the MUTE ON function key sending the
appropriate code via the RS-422 serial interface (see Section 7.9 at page 36). The amplifier can
be restarted in a similar manner provided a hardware shutdown is not in effect. The amplifier can
also be restarted by switching power off & on.
When the amplifier resumes operation, the attenuation level will return to its previous setting
after about 2 minutes of stable operation. Note however that the amplifier will not restart if a
FAULT condition is detected
7.7 A
F
LARMS AND
AULTS
Each unit continually monitors its internal temperature and current consumption. It also monitors
an automatic shutdown feature to prevent operation at excessive temperatures.
An ALARM will be triggered when the internal temperature of the unit exceeds 70°C. The unit
will continue to operate in this condition.
When the base plate temperature exceeds 80°C or the current consumption exceeds the threshold
value, a FAULT will be triggered and the unit will be put in shutdown. The unit will automatically
restart when its internal temperature cools under 65°C. If a fault has been caused by any other
condition, the status of the unit must be reset (i.e. to NO_FAULT) and the source of the problem
corrected before the unit can resume operation (see RESETTING THE UNIT below).
A thermal alarm can be caused by any of the following conditions:
• High ambient temperature (each unit is designed to operate between -30°C and +55°C
ambient).
• Blockage at air intake or exhaust.
• Cooling fan failure.
A VSWR higher than 3:1 at the RF output will generate a FAULT and will cause a software
shutdown after 1 sec. delay. The alarm and fault conditions can be detected via both the serial or
discrete interfaces
7.8 R
ESETTING THE
After a FAULT condition has been detected on a unit and the problem remedied, the controller
must be reset in order for the unit to resume operation. Similarly, unforeseen circumstances
might require default parameters to be reset.
U
NIT
AWMA-C250
Page 35
Advertisement
Table of Contents
