Yokogawa DAQWORX - Manual (Page 59)

4-12 IM WX102-01E
• RL : Rate-of-change lower-limit alarm. An alarm occurs when the measured value
changes in the decreasing direction within a certain time (rate-of-change alarm
interval) and exceeds the lower-limit alarm setpoint.
• dH : An alarm occurs when the difference between two channels exceeds the upper-
limit alarm setpoint. This only applies to a channel for which interchannel
differential computation is selected, and can be set as a type of alarm.
• dL : An alarm occurs when the difference between two channels exceeds the lower-
limit alarm setpoint. This only applies to a channel for which interchannel
differential computation is selected, and can be set as a type of alarm.
See also Section 4.20, “Setting Alarm Interval, Hysteresis, and Alarm Display Hold.”
Only H (upper-limit alarm) and L (lower-limit alarm) are available for computation
channels.
Note
• Alarms can’t be set if the input type is SKIP, or if the Math channel mode is OFF.
• If you make below changes, channel alarms will automatically be switched OFF:
• Input type.
• Measurement range.
• Reference channels of inter-channel computations.
• RRJC reference channels, reference channel inputs, or thermocouples.
• Setting Math channels ON, OFF, Math equations
Setting alarm values
Set one alarm value for each alarm number within the following range, depending on the
type of input. The default value is 0 (zero).
H and L
• VOLT, TC, RTD, DI, DELTA, AC, STRAIN, mA, and PULSE: Within the measuring
range in the related channel. DI can be set to either 0 or 1.
• SCALE: Within a linear scaling value.
• Math channel: Within the range specified by the Math function.
RH and RL
• VOLT, TC, RTD, DI, and DELTA, AC, STRAIN, mA, and PULSE: Within 1 to [maximum
measuring range minus minimum measuring range] in the related channel. For
example, set 30000 (without using a decimal point) if the maximum value exceeds
30000. DI can be set to only 1.
• SCALE: Set 1 to 30000 without using a decimal point.
dH and dL
• When the reference channel uses VOLT: Within the measuring range.
• When the reference channel uses other than VOLT: [maximum measuring range
minus minimum measuring range] to - [maximum measuring range minus minimum
measuring range]
4.4 Alarm Settings