EPC
SERVO AMPLIFIER MODULE
Part Number L723888-3xx
ELECTRONIC
Telephone: (231) 929-1660
Oilgear
Fax:
(231) 929-7879
1424 International Dr
Issued May 31, 2018
Web Site:
www.oilgear.com
Traverse City, MI USA 4 9 6 8 6
Bulletin 836260F
16
Pressure Feedback Source
: The Pressure Feedback Source selects the source of the pressure
feedback for the program. Valid entries are (1) Analog Input 1, (2) Analog Input 2, (3) Analog Input
3, (4) LVDT 1 (Analog Input 4), or (5) Ramp 1.
Program Output Destination
: The Program Output Destination selects the output of the program.
Valid entries are (0) Pump Controller or (1) Direct. If the Pump Controller is chosen, the output of the
Program will be the input to the Pump Controller module. If Direct is chosen, the output of the Program
will by-pass the Pump Controller module and is passed directly to the servo driver. Under most
circumstances, the Pump Controller should be chosen as the output destination.
KP
: KP provides the proportional gain setting to control the pressure limit slope. KP is configured as
a percentage, with 0% to no proportional gain and 100% equivalent to maximum proportional gain.
Pressure Breakpoint Preset:
The Pressure Breakpoint Preset allows for direct numeric input. The
preset has a slightly different characteristics depending on the value of its entry.
If the Pressure Breakpoint Source is set to
0 (Preset Value)
, the preset is configured as a
percentage, with 0% equivalent to a 0VDC input signal and 100% equivalent to a +10VDC signal.
This value is used as the Pressure Breakpoint command.
If the Pressure Breakpoint Source is set to
6 (Limit Offset)
, the preset is configured as a
percentage, with 0% equivalent to a 0VDC input signal and 100% equivalent to a -10VDC offset
signal. The offset value is added to the Pressure Limit Source signal to make the Pressure
Breakpoint command.
Finally, if the Pressure Breakpoint Source is set to
7 (Limit Attenuation)
, the preset is configured as
a percentage of the Pressure Limit Source, with 0% equivalent to a 0VDC input signal and 100%
equivalent to the Pressure Limit Source. This value is used as the Pressure Breakpoint command.
Pressure Breakpoint Source:
The Pressure Breakpoint Source selects the source of Pressure
Breakpoint command. Valid entries are (1) Analog Input 1, (2) Analog Input 2, (3) Analog Input 3,
(4) LVDT 1 (Analog Input 4), (5) Ramp 1, (6) Limit Offset, (7) Limit Attenuation, (8) Reference
Offset or (9) Reference Attenuation.
Program Overview
: The Flow with Pressure Limit Control Program is a sloping pressure limiting
control program similar to the control schemes used in Oilgear Analog Rack systems.
The algorithm will begin to limit the Flow command once the Pressure Feedback value is greater than
the Pressure Breakpoint command. Comparing the Breakpoint command to the Feedback value
produces an error value. The error is multiplied by the KP constant to produce the Yp limit signal,
which is summed with the full-scale command. The summation of the full-scale command and the
YP limit signal in turn sets a limit to the Flow command. If the Breakpoint Pressure Limit command
is greater than the Feedback signal, the Flow command will only be limited by the full- scale
command.
If using EPC software version 1.06 or earlier, see Appendix A for Generation 1 control.
