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About this product
Bosch Rexroth AG
, VT-MRMA1-1, RE 30214-B/03.2019
The current ramp time can be established according to the following formula from
the voltage of the measuring signals (switch position 4 or 5) at test jack v (front):
The following table shows the value measured at the test jack and the associated
current ramp time:
Table 8: Ramp times
Table 9: Pressure command value attenuator
Purpose
Effect
Setting
Limits the maximum actual
pressure value
The internal pressure
command value is influenced.
With potentiometer
G
W
: 0 %
to 130 %
Example: Application with pressure stage having a nominal value of 100 bar
A voltage applied by the machine control corresponds to 10 V (= 100 %) at input wp.
A max. pressure of 80 bar (= 80 %) is to be possible. Potentiometer Gw is used to
adjust the internal pressure command value to a voltage of 8 V (= 80 %) (voltage at
test jack v with switch position
0
). With an applied pressure command value of 10 V,
this corresponds to an actual pressure value of 80 bar.
Table 10: Linearization
Purpose
Effect
Setting
Compensation of a non-linear
valve characteristic curve
Generates the valve position
command value from the
pressure command value
None
Table 11: Linearization
Purpose
Effect
Setting
Internal limitation of the valve
position command value
(irrespective of the pressure
command value applied).
Safety limitation of the valve
stroke to +110 % and -5 %
None
5.2.4 Controller and functions closely related to the controller
The description refers to functions that are directly or indirectly related to the
position controller in functional terms.
Table 12: Valve position controller
Purpose
Effect
Setting
Generation of output variable
for clocked output stage
from the system deviation of
position.
Matching of the actual
valve position value with
the internally applied valve
position command value.
None
t = • 1 [sec]
1 V
U
t
Value at test jack position
4, 5
U
t
in Volt 10
5
3
2
1
0.5
0.01
0.05
0.03
0.02
0.01
Current ramp time (±20 %)
t in sec 0.1
0.2
0.33
0.5
1
2
10
20
33.3
50
100
Pressure command value
attenuator (4)
Linearization of valve
characteristic curve (5)
Amplitude limiter (6)
Valve position controller
(7)
