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4.1.3 MANUAL MODE FOR PROPORTIONAL OUTPUTS
Manual adjustment of the proportional output(s) can be used to test the operation of the
output(s), while tuning to establish basic process control, or to provide control of the propor-
tional output(s) during the occurance of certain error conditions.
Note: The proportional output(s) do not change automatically in response to changes
in the process while in the Manual mode. Be sure to pay close attention to the process
to avoid damage.
To enter the Manual mode, press and release the AUTO/MAN key for the specific pen. If the
Standby mode is on in the Enable mode and a control output is selected for proportional
control, the instrument will enter the Manual mode. The Manual mode status LED will light for
that pen to indicate that the Manual mode is in use. Shifting from the Control to the Manual
mode is bumpless. The proportional output(s) will stay at the last value(s) calculated by the
control algorithm. Po1 will appear on the display if output 1 is a proportional output or Po2 if
output 1 is not a proportional control.
In order to vary a proportinal output value, press and release the SCROLL key until the
display code for the output is displayed Po1 or Po2. Press the SCROLL key to see the
percentage of output value. Press the UP key to increase the output percentage value. Press
the DOWN key to decrease the output percentage value.
If no keys are pressed, the display will sequence through the following displays:
Po1 if output 1 is 3, 4, 5, 6, 7 then the output 1 percentage of output value.
Po2 if output 2 is 3, 4, 5, 6 then the output percentage of output value.
Proc will be displayed then current process value for that pen.
In order to change a proportional value once the cyclic display begins, press and release the
UP or DOWN key then press the SCROLL key until the display code for the output is dis-
played Po1 or Po2. Press the SCROLL key again to see the percentage of output value.
Press the UP key to increase the output percentage value. Press the DOWN key to decrease
the output percentage value.
To return to the Control mode of operation from the Manual mode, press the specified AUTO/
MAN key. If the Automatic Transfer feature is selected in the Program mode, the instrument
will switch from the Manual mode to the Control mode when the process value reaches the
setpoint value.
Alarm Operation 4.2
There are two alarms available per pen. The type of alarm is selected in the Program mode
as follows:
1. Process Alarm Direct - the alarm will be on if the process value is greater than the process
value selected.
2. Process Alarm Reverse - the alarm will be on if the process value is less than the process
value selected.
3. Deviation Alarm Direct - the alarm will be on if the process value is greater than the
setpoint plus the deviation value selected.
4. Deviation Alarm Reverse - the alarm will be on if the process value is less than the
setpoint plus the deviation value selected.
5. Deviation Band Alarm Open Within - the alarm will be on if the process value is greater
than one half the deviation band alarm values selected above or below the setpoint.
