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
4.5.2 Ramp Configuration
The EPC module provides one ramp module and is configured by program items 870 through 874. The
ramp can be configured from the Advanced Configuration Form (select Diagnostics and then
Advanced).
Program Item Range
Description
870
0 to 4
Ramp 1: Source
871
1 to 255
Ramp 1: Acceleration Rate
872
1 to 255
Ramp 1: Acceleration Step
873
1 to 255
Ramp 1: Deceleration Rate
874
1 to 255
Ramp 1: Deceleration Step
Table 17: Ramp Configuration
Source
: The Source selects the Analog Input used as the ramp input. Valid entries are (0) No
Ramp, (1) Analog Input 1, (2) Analog Input 2, (3) Analog Input 3, or (4) LVDT (Analog Input 4). If
No Ramp is selected, the ramp module will be disabled and the ramp function will be equal to
2048 DAC counts.
Rate and Step
: The Ramp module provides different ramping rates for acceleration and
deceleration.
Acceleration
is defined as increasing stroke, while
Deceleration
is defined as
decreasing stroke. Ramping from +5V to +10V is acceleration, while ramping from +10V to +5V is
deceleration. Ramping from -5V to -10V is also acceleration, since -10V provides greater stroke
than -5V. Conversely, ramping from -10V to -5V is deceleration.
Since the EPC is a digital controller, the ramp is actually a staircase-like signal. The
Rate
describes
the time length of each step and is expressed in whole number multiples of the closed loop update
rate. The
Step
describes the potential step at each interval and is expressed as DAC counts.
The closed loop response is 1600 Hz. The Ramp Rate can be expressed in Volts/second with the
equation
𝑅𝑎𝑚𝑝 𝑅𝑎𝑡𝑒 (
𝑉𝑜𝑙𝑡𝑠
𝑠
) = [𝐶𝑙𝑜𝑠𝑒𝑑 𝐿𝑜𝑜𝑝 𝑅𝑒𝑠𝑝𝑜𝑛𝑠𝑒] × 0.004884 ×
𝑆𝑡𝑒𝑝
𝑅𝑎𝑡𝑒
The larger the ramp rate or step is, the more course the ramp stair casing will be. The time length of
each step can be computed from the Rate setting:
Time Length (seconds)
𝑅𝑎𝑡𝑒
[𝐶𝑙𝑜𝑠𝑒𝑑 𝐿𝑜𝑜𝑝 𝑅𝑒𝑠𝑝𝑜𝑛𝑠𝑒]
Potential Step (Volts)
Step
0.004884
50
