GDS-68XP Operation & Maintenance Manual, Revision 3.5
Page 25
SEQUENCE
Switch
Sequence
Time
Purge / Hold
Time
Total Cycle Time
(Approximate)
0
On-Demand Sequence
1 hour
1
12-15 min
40 min
1 hour
2
12-15 min
105 min
2 hours
3
12-15 min
165 min
3 hours
4
12-15 min
225 min
4 hours
5
12-15 min
285 min
5 hours
6
12-15 min
345 min
6 hours
7
12-15 min
465 min
8 hours
Figure 6-2: Sequence Timing
BYPASS
disables
the
sequencer
and
allows
sample
gas
to
flow
directly
into
the
sensor
for
testing
purposes.
To
enter
BYPASS
mode,
press
and
hold
the
BYPASS
button.
To
exit
Bypass,
press
and
hold
the
RUN
button.
Bypass
mode
will
automatically
exit
after
15
minutes
of
operation.
Bypass
is
only
available
during
Purge/Hold
sequence.
RUN
Pressing
RUN
for
five
seconds
during
the
Purge/Hold
sequence
will
initiate
a
new
cycle.
L1
AND
L2
indicate
the
status
of
the
sequencer
processor.
MODE
L1
(RED)
L2
(GRN)
PUMP
VALVE
DESCRIPTION
START
‐
UP
SIMULTANEOUS
FLASH
OFF
OFF
FIRST
8
SECONDS
ONLY
WARM
‐
UP
ALTERNATE
FLASH
ON
OFF
INITIAL
WARM
‐
UP
ONLY
3
ON
‐
DEMAND
SLOW
FLASH
OFF
ON
2
OFF
WAITING
FOR
REMOTE
“START”
ACTIVE
SAMPLE
SEQUENCE
CONDITION
1
FLASH
OFF
OFF/ON
1
ON
GAS
APPLIED
TO
SENSOR
FOR
10
SEC
DELAY
1
FLASH
OFF
ON
OFF
PURGE
AIR
FOR
FIVE
MINUTES
CHARGE
2
FLASHES
OFF
OFF/ON
1
ON
GAS
APPLIED
TO
SENSOR
READING
3
FLASHES
OFF
OFF/ON
1
ON
IDENTIFY
PEAK,
STORE
READING
RECOVERY
4
FLASHES
OFF
ON
OFF
PURGE
AIR
TO
<
10%
OF
FULL
SCALE
Purge
/
Hold
Mode
PURGE/HOLD
OFF
2
FLASHES
ON
2
OFF
SENSOR
AIR
PURGE
2
BYPASS
MODE
ALTERNATE
FLASH
OFF/ON
1
ON
RAW
SENSOR
INPUT
TO
CHANNEL
1
CAL
MODE
SLOW
FLASH
OFF
ON
OFF
PURGE
AIR
FLOWING
TO
SENSOR
1)
Pump
is
ON
if
sample
draw,
OFF
if
positive
pressure.
2)
Pump
runs
intermittently
3)
15
minute
warm
‐
up
starts
once
sensor
output
reaches
stable
value
(+/
‐
10%
of
scale)
Figure 6-3: L1 / L2 Indicator Operation