Output Parameter Module (2-Op); Time Proportioning Cycle Time (Cyct); Output Control Action (Opac); Output Power Limits (Oplo & Ophi) - Omega CN63100 Series User Manual

Output Parameter Module (2-OP)

The controller has parameters that affect how the main control output (O1)
and Main Linear DC output control signal responds to temperature changes
and sensor failures.

Time Proportioning Cycle Time (CYCt)

The selection of cycle time depends on the time constant of the process and
the type of output used.
CYCt - 0 to 250 seconds
For best control, a cycle time equal to 1/10 of the process time constant, or
less is recommended; longer cycle times could degrade temperature control,
and shorter cycle times provide little benefit at the expense of shortened relay
life. When using a Logic/SSR drive output with the SSR Power Unit, a
relatively short cycle time may be selected.
A setting of zero keeps the main control output and front panel indicator
off. This is useful if using the linear DC output signal for control. On some
models, output (O1) can be configured as an alarm output ACt1 under
Module "4-AL".

Output Control Action (OPAC)

For heat and cool applications, the main output (O1) is normally used for
heating (reverse acting) and the optional cooling output (O2) is normally used
for cooling (direct acting).
OPAC - rEv (Reverse acting)
drct (Direct acting)
If O2 (cooling) is not used, then the action can be reverse or direct acting.
When used for control output, the Main Linear DC output operation is
affected by this parameter.
Output Power Limits (OPLO & OPHI)
Enter the safe output power limits for the process. These parameters may
also be used to limit the minimum and maximum controller power due to
process disturbances or setpoint changes, to reduce overshoots by limiting
the process approach level.
OPLO & OPHI - 0 to 100%
If the cooling output is selected, the limits range from:
OPLO & OPHI - -100 to 100%
With Alarm 2 selected for cooling, the Lower Limit can be set to less than
0% to limit maximum cooling or set to greater than 0% to limit minimum
heating. Set the High Limit to less than 0% to limit minimum cooling or
greater than 0% to limit maximum heating. When controlling power in the
manual control mode, the output power limits do not take effect.

Sensor Fail Power Level (OPFL) CN63100 only

If a failed sensor is detected, the control output(s) default to a preset power
output.
OPFL - 0% (O1 output full "off") to 100% (O1 output full "on")
If Alarm 2 is selected for cooling , the range is extended from:
OPFL - -100% to +100%
At 0% both outputs are off, at 100% O1 is on and O2 is off, and at -100% O2
is on and O1 is off. The alarm outputs are up-scale drive (+9999) with an open
sensor, and down-scale drive (-9999) with a shorted sensor (RTD only),
independent of this setting. Manual Control overrides OPFL.

Output Power Dampening Filtering Time (OPdP)

The output power calculated by the PID controller can be dampened
(filtered) to reduce the controller output activity. Those processes with high
gain and/or derivative times, or those processes with a relatively high noise
content, can benefit from the dampening action.
OPdP - 0 to 250 seconds
The dampening parameter is expressed as a time constant in seconds.
Increasing the value increases the dampening or filtering effect. A value of
zero disables output power dampening. The amount of dampening to be used
depends primarily on the response time of the process and the amount of final
actuator activity desired. Generally, dampening times in the range of 1/20 to
1/50 of the controller's integral time (or process time constant) prove to be
effective. Dampening times longer than these may cause controller instability
due to the added lag effect of too much filtering.
In the case where a relatively high dampening time is desired, the
controller's proportional band may be increased to restore an adequate
stability margin. The Auto-tune procedure of the controller sets the
dampening value appropriate to the characteristics of the process.
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