EPC-250 IOI 6-18 All rights reserved © ALTRONIC, LLC 2018
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10.4
Reset Rate
Shows how often the PID error is calculated. The value range is from 1 to 10.
10.5
PID Output
The PID output is the error calculation. A well-tuned engine with a 0.2PSI dif-
ference between desired and actual air pressure should generate a PID Output
of 0.7 maximum. This can be used to adjust the gain setting. Refer to the
trend until there is minimal oscillation on the waste gate output.
10.6
Max Controller Output:
Max Controller Output limits the maximum PID output. During large engine
swings this function governs the PID output in order to prevent the PID from
chasing the engine swings, thereby avoiding an output that is too large to
control. The range of this value is from 1 to 99.
10.7
AO1 Min/AO1 Max
This is Analog Output 1 on the I/O board. This output is scaled from 0 to 100,
where 0 equals 4mA and 100 equals 20mA. AO1 Min/AO1 Max limits the
lower and upper range of the analog output. This is useful if the waste gate
sticks when it is below or above a certain value.
10.8
Calc AO1
This is the Calculated Analog Output.
10.9
WG Output
This is the actual position of the waste gate.
10.10
Deadband
If the desired air manifold pressure is above or below the actual air manifold
pressure by the amount of the deadband value, the controller will respond to
this error appropriately. For example, with a deadband of zero, any difference
between the actual and the desired air manifold pressure will initiate a control-
ler response. With a deadband of 1, the desired air manifold pressure must be
greater or less than 1 to initiate a controller output. This can be used with a
pulsating air manifold pressure signal.
10.11
PID-Forward Action Enabled
This is used to control the mode of the PID signal from forward acting to re-
verse acting. In forward acting mode 0 = 4mA, 100 = 20mA. In reverse acting
mode 0 = 20mA and 100 = 4mA.
10.12
WG-Auto Enabled
This button toggles the waste gate control from auto to manual. Pushing the
Sync button makes the manual waste gate setpoint equal to the auto waste
gate output, but does not automatically switch the output to auto/manual or
manual/auto. Once synchronized, the WG-Auto Enabled button turns green.
Pressing the Auto/Manual button switches the controller to manual/auto or
auto/manual. The Sync button is required to prevent an engine shutdown
due to a difference between controller output (4-20mA) in manual mode and
controller output (4-20mA) in auto mode. The greater the difference, the more
time will be required for the values to synchronize.
10.13
Home position
If enabled, the waste gate output will revert to the home position during a fault
or an engine shutdown. Entering a negative value in the RPM setpoint box
keeps the controller in automatic mode. Entering a positive value enables the
home position feature. During an engine shutdown the waste gate will move to
the home position setpoint. When the engine is started the controller will go
into automatic mode when the RPM is greater than the RPM setpoint.
10.14
Auto/Manual
In Auto the EPC-250 automatically goes into controlling mode when RPM is
above the home position reset value. In Manual mode the reset button on the
home page must be pressed in order to enter the auto mode. When input 31
is closed, exceeding the top or bottom limit will reset the EPC-250 if it is in
manual mode.
Note: The home position is typically
closer to the running position. In the
case of a 2400 Superior the home
position would be 100. This engine
cannot have any air while starting in
ramping to idle.
