SRS Labs CTC100, Руководство пользователя

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Remote Programming 107
CTC100 Programmable Temperature Controller
The input must be stable before either Step or Relay tuning is started. Furthermore, the output
must be greater than half the step height before relay tuning is started. The best time to start a step
response is when the system is first turned on at the beginning of the day, i.e. the heater is cold
and its temperature stable. After the step response finishes, the feedback mode changes to manual
and the heater ramps up to the setpoint. Once the temperature is stabilized at the setpoint, relay
tuning can be used to produce more accurate PID parameters. When relay tuning is complete, the
PID mode changes to manual.
Errors: Attempting to set the PID mode when no PID input channel is selected produces a run-
Channel. PID.Ramp 0.0
Ramp rate. Determines the setpoint ramp rate in degrees per second. If the ramp rate is
nonzero, whenever the feedback setpoint is changed the feedback will gradually ramp the
temperature to the new setpoint. If the ramp rate is set to zero, setpoint ramping is disabled and
the CTC changes the temperature at the fastest possible rate.
Errors: Attempting to set the ramp rate when no PID input channel is selected produces a run-
Channel. PID.RampT 0.0
Ramp temperature. The ramp temperature is an internally-generated setpoint for the PID
feedback loop; it is the temperature that the CTC100 is trying to maintain at the present moment.
If the feedback is not running, the ramp temperature always equals the sensor temperature, since
the CTC100 has no control over the sensor temperature when the feedback is not running. When
the feedback is started, the ramp temperature automatically increases or decreases at the ramp rate
until it reaches the setpoint. This feature allows you to bring your system up to its operating
temperature at a controlled rate. The actual temperature of your experimental system should
ideally follow the ramp temperature, perhaps lagging a few seconds behind, depending on how
quickly your system responds and how well the PID parameters have been tuned.
Once it reaches the setpoint, the ramp temperature remains at the setpoint as long as the
feedback is running. If the setpoint is changed, the ramp temperature automatically increases or
decreases at the ramp rate until it reaches the setpoint. If the feedback is disabled, the ramp
temperature immediately begins to track the sensor temperature.
To start a temperature ramp, enable the feedback, set the ramp rate, and then change
Channel .PID.Setpoint
to the desired end point of the ramp. In general, the ramp temperature
should not be directly set by the user, except perhaps as a way to cancel a ramp; for example,
Out1.PID.RampT = #Out1.PID.setpoint
tells the CTC100 to stop gradually ramping the temperature and instead proceed as quickly as
possible to the setpoint. On the other hand,
Out1.PID.setpoint = #Out1.PID.RampT
stops ramping by freezing the temperature at its current value.
The following line can be used to pause a macro until the ramp is complete:
while (Out1.PID.RampT != Out1.PID.setpoint){ pause 1 s }
Errors: Attempting to set the ramp temperature when no PID input channel is selected
produces a run-
Channel. PID.Setpoint 0.0
Determines the PID setpoint. The PID loop attempts to keep the input at this value by changing
the output.