Yokogawa PC-Based MX100 - Manual (Page 43)

4
IM MX100-0E
Alarm Type
The following six alarm types are available.
When not using differential input on measurement channels, select OFF, High, or Low.
When using differential input, select OFF, dHigh, or dLow. On computation channels,
select OFF, High, Low, rHigh, or rLow.
• Upper limit alarm (High)
Generates an alarm when the measured or computed value is greater than or equal to
the alarm value.
• Lower limit alarm (Low)
Generates an alarm when the measured or computed value is less than or equal to
the alarm value.
• Differential upper limit alarm (dHigh)
Generates an alarm when differential input values (difference between the measured
value of a channel and that of the reference channel) are greater than or equal to the
alarm value.
• Differential lower limit alarm (dLow)
Generates an alarm when differential input values (difference between the measured
value of a channel and that of the reference channel) are less than or equal to the
alarm value.
Alarm value
Alarm reset
Alarm occurrence
Upper limit alarm
Differential upper limit alarm
Lower limit alarm
Differential lower limit alarm
Measured value
or computed value
Alarm reset
Alarm value
Alarm occurrence
Measured value
or computed value
• Upper limit on rate-of-change alarm (rHigh)← setting only on computation
channels
Generates an alarm if the amount of change in the computed value in the rising
direction exceeds the alarm value within the rate-of-change detection interval.
• Lower limit on rate-of-change alarm (rLow)← setting only on computation
channels
Generates an alarm if the amount of change in the computed value in the falling
direction exceeds the alarm value within the rate-of-change detection interval.
Computed value
Change in the
computed value
T 1
Time
T 2
t 1 t 2
Amount of change
in the setting |T 2 –T 1 |
T 2
Time
T 1
t 1 t 2
Change in the
computed value
Interval
t 2 –t 1
Interval
t 2 –t 1
Upper limit on rate-of-change alarm Lower limit on rate-of-change alarm
Computed value
Amount of change
in the setting |T 1 –T 2 |
The rate-of-change detection interval is the measurement interval × measurement count.
Select that measurement count (1 to 15) in the Rate-of-change alarm interval setting in
the Meas. Channel settings.
Note
Do not close the connection between the MX100 and PC software. Computation channel alarms
will not occur because the computation function does not work when using only the MX100.
Operations of the MX100 Standard Software