52
7.3.6 AUTOMATIC OR MANUAL START-UP
The ATC770 will allow for manual start-up and ramp to set point prior to controlling the process, or
it can go directly to Automatic Start-Up where is controls the set point based on the previous data.
This is generally a bad idea in motor control processes, and is discouraged.
However, in some non-motor control applications, it is desirable. To change the Manual/Auto Start-
Up parameter, press the FUNC key until
nonE
and
GROUP
show on the display. Press the ▲ key
until
3
shows in the upper display. Press the FUNC key until the lower display shows
MA.STP
. The
default will be manual
(nAn)
. To change to automatic start-up, press the ▼ or ▲ key until the upper
display changes to
AUTO
. Press the FUNC key to set the value. Press the A/M key to return to the
main screen.
7.3.7 MANUAL/AUTOMATIC TRANSFER
When transferring from manual control to Automatic control there are two methods: Bumpless
Mode (without modification of setpoint) and Set Point mode (where the current Set Point is modified
from the set point and PID parameters in memory).
To change the Manual/Automatic Transfer parameter, press the FUNC key until
nonE
and
GROUP
show on the display. Press the ▲ key until
4
shows in the upper display. Press the FUNC key until
the lower display shows
MA.TRF
. The default will be bumpless
(bmPL)
. To change to Set Point
modification, press the ▼ or ▲ key until the upper display changes to
SP
. Press the FUNC key to set
the value and move to the next parameter, Set Point Ramp
(SP.RMP)
.
Set Point Ramp determines how fast the manual setpoint is changed to the stored setpoint. It is active
during the change from local to remote set point and vice versa. This parameter is used to limit the
rate of change of the setpoint to minimize process irregularities. When the ramp value reaches the
remote or stored setpoint value, the function is disabled to allow for controller set point to match the
analog input.
After setting the
MA.TRF
parameter, the Set Point Ramp parameter will appear. The lower display
will show
SP.RMP
. The default will be
OFF
. To change to Set Point Ramp, press the ▼ or ▲ key until
the upper display changes to the appropriate rate of change of pressure units per second, from 1 to
999/second. Press the FUNC key to set the value. Press the A/M key to return to the main screen.
7.3.8 TUNED PARAMETERS, AFTER SMART “TUNING”
After the ATC770 has run the SMART (TUNE) function, the following Read-only values in Group 9
will change from their defaults:
Process Time Delay:
(AT.TO)
will display the Process Time Delay value as estimated by the SMART
(TUNE) function in hundredths of a second. The display will show zero until the first Smart trial.
Process Time Constant:
(AT.TAU)
will display the Process Time Constant value as estimated by the
To Next Page
Loading...
Need help?
General
