ABB 800xA Operation page 52

Tuning Via the Loop Detail Display
Entered value goes red after it is written to the controller. Once the new value
come back from the controller it changes back to black.
Changing Limit Parameters
Alarm limit parameters include: InputHiHi, InputHi, InputLoLo, and InputLo
Measured Variable; Input Rate of Change; and Output Rate of Change. Control limit
parameters include: high and low limits for setpoint (SetpointHi, SetpointLo),
deviation, and output. Each of these parameters requires a value entry in the Limit
column. All conditions in this area can be switched between Enabled (checked) and
disabled, and priorities can be set to Standard, High, or Medium.
Quality parameters include: InputBad, SetpointBad, DeviationBad, and OutputBad.
Changing a Loop Parameter
Loop parameters include: phase, scan rate, loop mode, trend rate, alarm posting, and
alarm checking. Phase, scan rate, and trend rate parameters require value entries, the
loop mode can be switched between scan ON and scan OFF, and alarm posting and
alarm checking can be switched between Enable and Disable.
When changing the trend rate, select one of the following valid choices: 0, 6, 12, 60,
120, 360, 720, 1440, and 2880.
Scan Rate equals the Processing Rate divided by the Base Rate. If the Base Rate is
0.5 and the Processing Rate is 1.0, then the Scan Rate is 2.0. Changing the Scan
Rate here actually changes the Processing Rate using the same calculation.
To change a loop mode parameter (list selection):
1.
2.
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Select the Loop Mode value field in the Tuning area of the display. This
displays a pull down list to the right of the current field.
To change Loop Mode, select the setting you wish to change.
Changes made to any of the parameters on the
Loop Detail Display are not made to the database
until you press Enter. Value is reset if focus is lost.
Section 3 CCF Displays
3BUR002418-600 A