Honeywell 7800 Series Manual page 30

RM7888A
OPERATION
Fig. 23—DSI On/Off Stepfire sequence diagram.
KEYBOARD DISPLAY MODULE (FIG. 24)
The keyboard contains four pushbuttons and each has
separate functions (SCROLL-Down, SCROLL-Up, MODE
and Change-Level). The MODE and Change-Level func-
tions, when pressed together, provide a SAVE function.
1. Scroll Down-Up pushbuttons (◊) (see Fig. 25.
The scroll Down-Up pushbuttons (◊) are used to scroll
through the selectable messages. The double-headed arrow
(◊), which is located in the lower left position of the second
line of the display, represents the SCROLL Down-Up
pushbuttons. The SCROLL Down-Up pushbuttons (◊) can
be pressed to display the selectable messages one at a time
65-0175
STANDBY
INPUT &
OUTPUT
SIGNALS
STANDBY-
PURGE
POWER
POWER
PILOT
FLAME
MAIN
ALARM
IGNITION- T10
PILOT- T8
MAIN- T9
AIR VALVE-T5
FLAME PROVEN- T21
ALARM- T3
MOTOR POSITION- T12-T15 L/H/MOD
@ LOW FIRE INPUT- T18
LIMITS COMPLETE- T7
SF1 SPECIAL FUNCTION- T6
SF2 SPECIAL FUNCTION- T17
SF3 SPECIAL FUNCTION- T19
SF4 SPECIAL FUNCTION- T20
FLAME SENSED
OFF/ON OFF/ON
STEPFIRE- STEPFIRE-
PART 1 PART 2
5 TO
INFINITE
4 SECONDS
SECONDS
POWER POWER
POWER
PILOT PILOT
FLAME FLAME
MAIN
MOD MOD
TO STANDBY
or held down to scroll through the selectable messages at a
rate of two per second. When the last item of the selectable
messages is viewed, the display wraps around and again
displays the first selectable message.
2. Change-Level pushbutton (↔) (see Fig. 26).
The Change-Level pushbutton is used to change be-
tween the first hierarchy of selectable messages to a subset
of selectable messages. The symbol (>) located on the
second line in the lower right corner of the VFD represents
a first level hierarchy of selectable message. The symbol
(<) located on the second line in the lower right corner of
the VFD represents a subset of selectable messages.
30
M9492