Maple Systems OIT Family (ASCII) - Manual (Page 28)

2. All alarms are stored in an alarm stack which is internal to the OIT. The alarm stack
ensures that all alarms that are sent to the OIT by the ASCII host are stored until the
OIT operator has a chance to view them.
3. Each alarm can be configured to sound an internal or external alarm buzzer to get the
attention of the OIT operator on the plant floor. The Alarm LED (OIT3250 and
OIT4450 only) also blinks to indicate that an alarm has occurred.
Like message screens, alarm screens are capable of:
• displaying text and characters from the extended character set
• displaying up to 25 register monitors
• sending the screen contents to a printer for hard copy
• displaying the current time and/or date from the OIT’s real time clock
• displaying one line of horizontal scrolling text up to 128 characters long
• displaying blinking characters
Because of their special role, alarm screens are incapable of:
• chaining to message screens
• displaying for a preset length of time from 1 to 255 seconds
• beeping on display for two seconds
• help screens are not available
• being reviewed using the Last Message and Next Message keys.
AlarmshavethehighestpriorityfordisplayontheOIT.Thismeansthatanyalarmscreenrequested
bytheASCIIhostisdisplayeduntiltheOIToperatorpressestheAlarmAckkey.Forexample: The
ASCII host sends an alarm request. Because it is an alarm, the prior message is immediately re-
placed by the alarm, the alarm buzzer sounds, and the alarm LED blinks (if available).
The OIT is now displaying an alarm which must be acknowledged by the OIT operator. All
requests by the ASCII host to display screens other than alarms are now ignored by the OIT
until the Alarm Ack key is pressed or the alarm is cancelled by the ASCII host (refer to the
“Status Bit Coils” section). Similarly, any keys on the OIT which display screens will be ig-
nored. The OIT operator hears the alarm, rushes over to the OIT, and acknowledges that he
has seen the alarm by pressing the Alarm Ack key.
FEATURES 27
1010-0088, REV02
Bzz
zzz...
2 3 4 6 5 7 8 MESSAGE ALARM RUN PRINT 1
0
7
4
8
5
1 2
9
6
3
. PAGE
ACK
ALARM
DOWN
MESSAGE
PAGE
UP
NEXT
LAST
MESSAGE
TOGGLE HELP
SETUP
PRINT
SCREEN
DELETE
CLEAR
E
N
T
E
R
F1 F5 F9
F2 F6 F10
F3 F7 F11
F4 F8 F12
Caution!
Bottle not capped!
Caution!
Diverted offline.
Alarm #31