Precision Digital PD138 - Manual (Page 28)

PD138 Minimux
®
II Temp & Process Scanner Instruction Manual
28
ALARM SEQUENCE EXAMPLES
Sequence A
The PD138 is
scanning all the
selected inputs and is
currently at channel 2,
as indicated by a
green LED. After the Minimux
®
II
has dwelled on
channel 3 for the
appropriate settling
time, it poles channel
3’s alarm-in line and
finds it to be in alarm.
The LED starts
flashing yellow (red
and green), the horn
sounds and the alarm
relay transfers.
The unit continues to
scan other points and
an operator
acknowledges the
alarm. The internal
horn is silenced, the
alarm relay transfers,
and the number 3
LED goes to steady
red.