Yokogawa JUXTA VJU7 - Manual (Page 5)

5
IM 77J01U07-01E 4th Edition Feb. 09, 2007-00
9.3 Settings Related to Alarm Output
Set the following parameters when the alarm output is speci-
fied for the output 2.
9.3.1 Alarm Setpoint
Set the alarm-1 setpoint and alarm-2 setpoint numerically in
E01: SET POINT1 and E02: SET POINT2 for thermocouple
input and RTD input or in E03: SET POINT1 and E04: SET
POINT2 for mV input. Set them in [
° C] for temperature input
or in [%] for mV input.
● Setting range: 0 to 100% of input range
● Setting resolution: 0.1 ° C (for thermocouple input and
RTD input), 0.1% (for mV input)
9.3.2 Direction of Alarm Action
Select the direction of alarm-1 action and that of alarm-2 ac-
tion from among HIGH ALM (high-limit alarm) and LOW ALM
(low-limit alarm) in E05: ALM1 ACTION and E06: ALM2 AC-
TION.
● To activate alarm status when input signal Ն alarm
setpoint, select HIGH ALM.
● To activate alarm status when input signal Յ alarm
setpoint, select LOW ALM.
9.3.3 Hysteresis
Set the alarm-1 hysteresis and alarm-2 hysteresis numeri-
cally in E07: HYSTERESIS1 and E08: HYSTERESIS2 for
thermocouple input and RTD input or in E09: HYSTER-
ESIS1 and E10: HYSTERESIS2 for mV input.
Hysteresis is a value added to the alarm setpoint in order for
an alarm status to be released (to normal) after the alarm
status has been activated. The alarm status will be released
in the following conditions, depending on the direction of
alarm action.
*
When HIGH ALM (high-limit alarm) is set: Alarm is re-
leased when input signal < (alarm setpoint - hysteresis).
* When LOW ALM (low-limit alarm) is set: Alarm is re-
leased when input signal > (alarm setpoint + hysteresis).
Set them in [ ° C] for temperature input or in [%] for mV input.
● Setting range: 0 to 100% of input range
● Setting resolution: 0.1 ° C (for thermocouple input and
RTD input), 0.1% (for mV input)
9.3.4 Alarm ON Delay and Alarm OFF Delay
Set the alarm-1 ON delay and alarm-2 ON delay numerically
in E11: ON DELAY1 and E12: ON DELAY2. Set the alarm-1
OFF delay and alarm-2 OFF delay numerically in E13: OFF
DELAY1 and E14: OFF DELAY2.
An alarm ON delay is a delay time from the establishment of
alarm conditions to its output; an alarm OFF delay is a delay
time from the establishment of return-to-normal conditions to
its output.
● Setting range: 0 to 999 seconds
● Setting resolution: 1 second (However, about 0.2 second
is to be added to the set time to prevent wrong opera-
tion.)
For example, when an alarm ON delay is set to 1 second,
alarm output is generated if alarm status continues for 1 sec-
ond or more after the input value exceeds the alarm
setpoint. Furthermore, when an alarm OFF delay is set to 2
seconds, alarm output is released if normal condition contin-
ues for 2 seconds or more after the input value has returned
to normal from the alarm status.
9.3.5 Direction of Relay Action
Select the direction of relay energizing in alarm-1 normal
condition and alarm-2 normal condition from among NRM
DE-ENERGIZED (de-energized under normal condition) and
NRM ENERGIZED (energized under normal condition) in
E15: RL1 ACTION and E16: RL2 ACTION.