Omega RD-MV100 Series, User Manual

Page: 37 / 299

1-19
Overview of Functions
1
Measured
value Measured
value
R alarm
T
1
Time
Interval
t
2
-t
1
Interval
t
2
-t
1
T
2
T
2
T
1
t
1
t
2
t
1
t
2
Variation
|T
2
-T
1
|
Variation
|T
2
-T
1
|
Time
r alarm
Upper limit on rate-of-change alarm Lower limit on rate-of-change alarm
The interval is defined by the following equation and is set in terms of the number of
measured data points.
Interval = Scan interval
×
number of measurements
Alarm hysteresis
This applies to upper and lower limit alarms on measurement channels.
A width (hysteresis) can be specified on the value used to set or release the alarm. This
prevents the alarm from being set or released repetitively when the measured value is
fluctuating around the alarm value. The hysteresis is fixed to 0.5% of the display span
(display scale if the range is set to [Scale]). The initial setting is [ON].
Alarm set point
Alarm release
Measured value
Alarm occurrence
1V
Hysteresis (approx. 0.5%)
1V
Measured value
Alarm release
Hysteresis (approx. 0.5%)
Alarm set point
Alarm occurrence
Upper Limit Alarm (H)
Lower Limidt Alarm (L)
Alarm output relay
If you are using a model with the optional alarm output relay (/A1 through /A3), a contact
signal can be generated according to the alarm conditions. For the procedure related to
setting the alarm output relay, see section 6.2, “Alarm Setting.”
The following functions can be specified on the alarm output relay. For details, see
section 6.4.
• When multiple alarms are set to one alarm output relay, notify the succeeding alarms
after the first alarm that causes the relay operation (reflash alarm function).
• When multiple alarms are set to one alarm output relay, operate the relay when all
specified alarms are active (AND function)
• Energize or de-energize the alarm output relay when the alarm occurs (energize/de-
energize function of the output relay).
• When the alarm changes from the ON state to the OFF state (return to normal
condition), turn OFF the output relay with an alarm ACK operation (output relay hold
function).
1.5 Alarm Function