38
6.2.3 S
ETTING
THE
F
ILTERING
FOR
A
LARMS
Filtering is an electrical method of averaging the input values over a period of time to arrive at a
smoother curve. This helps to eliminate short duration transients and spikes which can cause alarms,
but which may cause false or spurious readings.
The Alarm filter default is 0.4 seconds of filtering. To change this value, press the
FUNC
key until
nonE and GROUP show on the display. Press the
▲
key until
2 shows in the upper display. Press the
FUNC
key until the lower display changes to
A1.FL. Using the
▼
or
▲
keys, select the amount of
filtering desired, from none
(OFF) to five seconds. When finished, press the
FUNC
key to lock in the
value and advance to the next parameter. If finished, press
A/M
to return to the operating screen.
Similarly, you may configure Alarm 2
(A2.FL) and Alarm 3 (A3.FL).
6.2.4 S
ETTING
THE
H
YSTERESIS
FOR
A
LARM
Hysteresis is used to describe the amount that the reading must drop below the alarm point (in a
high alarm) or must rise above the alarm point (in a low alarm) to clear the alarm condition. This
helps to eliminate short duration alarms when operating near the alarm condition. To change or
view this value, press the
FUNC
key until
nonE and GROUP show on the display. Press the
▲
key
until
4 shows in the upper display. Press the
FUNC
key until the lower display changes to
A1.HYS.
The values for hysteresis can range from .1% to 10.0%. Press the
▼
or
▲
keys until the upper
display changes to the desired value. Press the
FUNC
key to lock in the value and advance to the
next parameter, or press
A/M
to return to the operating screen. Similarly, you may configure Alarm
2
(A2.HYS) and Alarm 3 (A3.HYS).
6.2.5 S
ETTING
THE
R
ESET
M
ODE
FOR
A
LARMS
The Alarm Reset Mode determines if the alarm resets itself once the alarm condition is been
corrected, or whether the operator must press a button to reset the alarm. The Alarm Reset Mode
default is automatic reset once the alarm has cleared. To change or view this value, press the
FUNC
key until
nonE and GROUP show on the display. Press the
▲
key until
4 shows in the upper display.
Press the
FUNC
key until the lower display changes to
A1.RES. The value for reset mode is either
Auto for automatic reset, or LAtCH for manual reset. Press the
▼
or
▲
keys until the upper display
changes to the desired value.
Press the
FUNC
key to lock in the value and advance to the next parameter, or press
A/M
to return
to the operating screen. Similarly, you may configure Alarm 2
(A2.RES) and Alarm 3 (A3.RES).
6.2.6 S
ETTING
THE
F
AILSAFE
M
ODE
FOR
A
LARMS
The Alarm Failsafe Mode determines how the alarms react in the event of a power failure to the
ATC770. In the failsafe mode, the alarms will activate in the event of power loss. In non-failsafe
mode they cannot activate on power loss. The Alarm Failsafe default is failsafe mode. To change this
value, press the
FUNC
key until
nonE and GROUP show on the display. Press the
▲
key until
4
shows in the upper display. Press the
FUNC
key until the lower display changes to
A1.FSM. The
Summary of Contents for ATC770
Page 19: ...ATC770 Microprocessor Based Pressure Process Controller 19 Fig 2 ATC770 Outline Drawing...
Page 23: ......
Page 30: ...30 Fig 6 Remote Set Point Jumper Location Board E...
Page 84: ...NOTES...
Page 85: ...NOTES...
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Page 88: ...DYNISCO INSTRUMENTS 38 FORGE PARKWAY FRANKLIN MA 02038 ATTN MARKETING DEPT Place Stamp Here...
