User's Manual

P. G. TM0060
2-3
2.2 FAULT REPORTING
2.2.1 General - The A238 amplifier incorporates a number of circuits to detect
deviations in important performance parameters. The unit reports alarm conditions to a
remote Monitor unit such as the Model PS212.
The various functions are described in this section and may also be referenced in Section
4 where the the programming of amplifier options is discussed.
2.2.2 Report Types The unit generates two types of reports depending on the status of
the amplifier as determined by the built in monitor circuits. Each type consists of a
numeric code sent as low frequency tones along the coaxial cable for decoding at the
monitor unit.
Under normal operation the unit will transmit an "OK" code at intervals of approximately
80 minutes. This enables the system monitoring unit to keep track that the whole system
is connected and operational. In this mode a local green NORMAL LED lamp is
illuminated on the side of the amplifier.
In the event that a fault is detected in the amplifier, as described later, a "FAULT" code is
transmitted on the cable at intervals of approximately 80 seconds. In this mode a local
red FAULT LED is illuminated on the amplifier. LEDS on the side of the unit indicate
which specific local condition is causing the overall FAULT condition as described in the
next section.
In each case the code transmitted identifies the transmitting amplifier by the FAULT
CODE programmed in that particular amplifier as described later in Section 4.6. Before
shipment PG programs each amplifier with an arbitrary code from 1 to 199 which is also
shown by a label on the outside of the unit.
NOTE: Older models of PG bidirectional amplifiers such as the A181 or A188 transmitted
only fault codes, but are compatible with the fault codes transmitted by the A238.
When used with a PS212 Monitor they should be entered in the ID list as "FAULT
ONLY" (TFO) type units. If the A238 is used with a PS200 PS/Monitor the OK
code transmission (STATUS option) should be disabled (section 4.4) as it will
cause the PS200 to display a FAULT alarm. Fault codes above 199 should not
be set on any amplifiers since they may be incorrectly interpreted by the newer
PS212.