99
Daily Max Time
Enter the maximum amount of accumulated on-time, in Hand or Auto modes, that the
relay can have between midnight and midnight the next day. If the time is exceeded, the
relay will deactivate, and a Daily Max Timeout alarm will be triggered. The alarm will
clear, and relay allowed to reactivate at midnight the next day.
If the relay was in Hand mode when the alarm was triggered, it will revert to whichever
HOA state it was in prior to being set to Hand.
To override the Daily Max Limit for the rest of the day, press Reset Output
Timeout.
5.3.28
Relay or Analog or Control Outputs, Disturbance Variable Control Mode
Only available for 4-20 mA and pulse relay output channels.
These control modes generate an output by combining contributions from a Primary control output, a Disturbance
Input, and a Trigger Input in a variety of ways. When the disturbance trigger discrete input is active, the distur-
bance input is multiplied by the primary output to determine the control percent output. An alternate calculation
trigger mode selection (Use Disturbance) is available to simply switch to the disturbance output when the trigger is
active (rather than combine the two values).
Some Example Applications
In-Line pH Control Adjusted for Flow
Direct feedback pH control in a pipe using a Primary Output of PID or Proportional control mode, with the Dis-
turbance Input using flow rate to provide a multiplier to adjust the output. This is primary feedback control with a
feedforward trim. No Trigger is required.
Chemical feed in proportion to Flow Adjusted for pH
If the incoming flow is variable but the pH of the water is relatively constant, feed the chemical using Flow Propor
-
tional control mode, with the Disturbance Input using the pH reading to provide a multiplier to adjust the output.
This is primary feedforward control with a feedback trim. No Trigger is required.
Alternate Control During Upset Condition
Some disturbance applications require switching from one control mode to a different control mode (or a similar
mode with different control settings) during an upset condition. The Primary Output could be set to Proportional
control of pH, with the Disturbance Input selected as a Flow Proportional control algorithm. A Trigger Input could
be selected as a relay output that activates if the flow rate is either too high or too low. These conditions would
trigger a switch from pH control to flow based control.
Output Details
The details for this type of output include the % output, HOA mode or Interlock status, alarms related to this
output, Primary Output %, Disturbance Input value, current cycle on-time, accumulated on-time, raw output (in
mA or pulses/min.), relay type, and the current control mode setting.
Settings
Touch the Edit icon to view or change the settings related to the output.
Minimum Output
Enter the lowest output %. If the output should be off at the set point, this will be 0%.
Maximum Output
Enter the highest output %.
Hand Output
Enter the output % desired when the output is in Hand mode.
Off Mode Output
Only for analog outputs. Enter the output mA value desired when the output is in Off
mode, or being Interlocked, or during a calibration of the sensor being used as an input.
The acceptable range is 0 to 21 mA.
