Red Lion PAXDP User Manual

Page 19

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19

ALARM

STATE

ON

OFF

Hys

SP1 - SPn

SP1

ON

SP1 + SPn

OFF

ON

Hys

TRIGGER POINTS

Band Inside Acting (Unbalanced Hys) =



ALARM

STATE

ON

OFF

Hys

SP1 + (-SPn)

SP1

ON

TRIGGER POINTS

Deviation High Acting (SP

< 0) =



ALARM

STATE

OFF

ON

Hys

SP1 - SPn

SP1

OFF

SP1 + SPn

ON

OFF

Hys

TRIGGER POINTS

Band Outside Acting =



ALARM

STATE

ON

OFF

Hys

SP1 - (-SPn)

SP1

ON

TRIGGER POINTS

Deviation Low Acting (SP

< 0)=



Enter desired hysteresis value. See Setpoint Alarm Figures for visual

explanation of how setpoint alarm actions (balance and unbalance) are affected

by the hysteresis. When the setpoint is a control output, usually balance

hysteresis is used. For alarm applications, usually unbalanced hysteresis is

used. For unbalanced hysteresis modes, the hysteresis functions on the low side

for high acting setpoints and functions on the high side for low acting setpoints.
Note: Hysteresis eliminates output chatter at the switch point, while time delay

can be used to prevent false triggering during process transient events.









HYSTERESIS VALUE



to



to



SETPOINT VALUE









OFF TIME DELAY

ON TIME DELAY



to



sec.



to



sec.

Enter desired setpoint alarm value. These setpoint values can also be entered

in the Display Mode during Program Lock-out when the setpoint is programmed

as



in Parameter Module 3. When a setpoint is programmed as deviation or

band acting, the associated output tracks



as it is changed. The value entered

is the offset, or difference from



.

Enter the time value in seconds that the alarm is delayed from turning on after

the trigger point is reached. A value of 0.0 allows the meter to update the alarm

status per the response time listed in the Specifications. When the output logic

is



, this becomes off time delay. Any time accumulated at power-off resets

during power-up.

Enter the time value in seconds that the alarm is delayed from turning off after

the trigger point is reached. A value of 0.0 allows the meter to update the alarm

status per the response time listed in the Specifications. When the output logic

is



, this becomes on time delay. Any time accumulated at power-off resets

during power-up.





OUTPUT LOGIC

 





RESET ACTION







Enter the output logic of the alarm output. The



logic leaves the output

operation as normal. The



logic reverses the output logic. In



, the alarm

states in the Setpoint Alarm Figures are reversed.

Enter the reset action of the alarm output.



= Automatic action; This action allows the alarm output to

automatically reset off at the trigger points per the Setpoint Action

shown in Setpoint Alarm Figures. The “on” alarm may be manually

reset (off) immediately by a front panel function key or user input.The

alarm remains reset off until the trigger point is crossed again.



= Latch with immediate reset action; This action latches the alarm

output on at the trigger point per the Setpoint Action shown in Setpoint

Alarm Figures. Latch means that the alarm output can only be turned off

by front panel function key or user input manual reset, serial reset

command or meter power cycle. When the user input or function key is

activated (momentary or maintained), the corresponding “on” alarm

output is reset immediately and remains off until the trigger point is

crossed again. (Previously latched alarms will be off if power up

Display Value is lower than setpoint value.)



= Latch with delay reset action; This action latches the alarm output

on at the trigger point per the Setpoint Action shown in Setpoint Alarm

Figures. Latch means that the alarm output can only be turned off by

front panel function key or user input manual reset, serial reset

command or meter power cycle. When the user input or function key is

activated (momentary or maintained), the meter delays the event until

the corresponding “on” alarm output crosses the trigger off point.

(Previously latched alarms are off if power up Display Value is lower

than setpoint value. During a power cycle, the meter erases a previous

Latch 2 reset if it is not activated at power up.)

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