32/96
Pressure and flow control system SYDFE1 series 2X, 3X
| Product description
Bosch Rexroth AG, Edition 10.2021, RE 30011-B
5.11.7 Test jacks on the front panel of control electronics VT 5041-3X
The command values for pressure and swivel angle are provided by the higher-level
control and can be measured at test jacks 1 and 3.
The actual values for pressure and swivel angle can be measured at test jacks 2
and 4.
The valve command value generated internally by the control electronics as well as
the acquired actual valve value of the pilot valve can be measured at test jacks 5
and 6.
The active swivel angle command value at test jack 7 is the command value that is
currently valid for the swivel angle controller. The value can differ from the swivel
angle command value at test jack 3 for the following reasons:
• When case drain compensation is active, a compensation value, which is related
to pressure, is added to the command value of test jack 3.
• When the master/slave function is active, the command value of the swivel angle
is read in at connections 18c(+)/20c(-).
• In the “regenerative” operating mode, the swivel angle command value of 0…+10
V ≙ -100 %...-100 % is internally converted into -10 V…+10 V ≙ -100 %...-100 %
(test jack 7).
• The power limiter can limit the swivel angle command value. The limiter’s being
active is signaled by LED “Power Limiter“ on the front panel.
On control electronics with power limitation, test jack 8 is used to adjust/measure
the power limit value.
Table 7: Test jacks
Assignment of test jacks
Test jack 1
Pressure command value
0...+10 V
Test jack 2
Actual pressure value 0...+10
V
Test jack 3
Swivel angle command value
-10 V...+10 V ≙
-100 %...+100 %
Test jack 4
Actual swivel angle value
-10 V...+10 V ≙
-100 %...+100 %
Test jack 5
Valve command value ±10 V
Test jack 6
Actual valve value ±10 V
Test jack 7
Active swivel angle command
value ±10 V
Test jack 8
1)
Power limit 0...+10 V
Test jack 9
Reference
Test jack 10
Reference
1)
Only with version with power limitation
5.11.8 Leakage compensation
As the operating pressure rises, the amount of internal leakage of the SYDFE1
control system increases. For this reason, a certain external swivel angle command
value is applied in order to exercise a pressure-dependent influence on the pump’s
displacement:
The pump’s displacement decreases at higher pressures.
The standard versions of the various control electronics therefore comprise
an automatic case drain compensation feature that constantly adds a certain
percentage of the actual pressure value as correction factor to the swivel angle
command value. This, however, results in differences between the externally
provided swivel angle command value and the actual swivel angle signal when this
compensation feature is activated.
In certain applications and with integrated, connected pressure transducer,
pressure fluctuations, which may occur during displacement operation (swivel
