Bosch Rexroth VT-VSPA2-1-2X/V0/T5 User Manual

18/40 Information on this product
Bosch Rexroth AG, VT-VSPA2-1-2X/V0/T., RE 30110-B/11.2012
5.2.4 Description of the functions and components of the analog amplifier card
The assemblies described in this documentation are shown in the block diagrams (data
sheet 30110). The numbers in brackets used in the following description are cross-
references to the block diagrams in Fig. 1 and Fig. 2 on page 14 and page 15.
5.2.4.1 Power supply unit [1]
The amplifier card is equipped with a power supply unit with a making current lim-
iter. It supplies all positive and negative supply voltages required internally. The mak-
ing current limiter prevents high start-up peaks caused by the smoothing capacitors
in the power output stage.
5.2.4.2 Command value specification
The internal command value signal is calculated from the total (summation[6]) of
the following signals:
• The external command value signal at the differential input [2]
• The external command value signal at the current input [3]
The zero point offset [5] (zero point potentiometer "Zw")
The zero-point offset (command value zero point setting) is used to correct the
zero signal at the input and can be used as command value specification for step
setting by means of targeted trimming (compensation of hydraulic valve overlap).
• The called up signal
The following applies:
Standard
values
Input signals
Command value
measuring socket
Flow direction
Current input or Differential input
–100 % 4 mA –10 V –10 V P to B;
A to T
0 % 12 mA 0 V 0 V
100 % 20 mA 10 V 10 V P to A;
B to T
0 % < 1 mA
1)
0 V
1)
If the current input is not wired-up or if the cable of the current command value is broken, the
resulting internal command value signal is 0%.
There is no switching between current and voltage input. The inputs are permanently
available (see terminal assignment).
Four command value signals "w1" to "w4" can be called up. The external command
value voltages (command values 1 to 4) are either defined directly by the regulated
voltage outputs +10 V and –10V or external potentiometers. If these command value
inputs are directly connected to the regulated voltages, the command values are set
at the potentiometers "w1" to "w4". When using external potentiometers, the internal
potentiometers will function as attenuators or limiters.
Only one call-up can be operated at the same time. If several call-ups are operated
simultaneously, call-up "1" has the lowest priority and call-up "4" has the high-
estpriority.
The respective active call-up is indicated via a yellow LED on the front plate.
Internal command
value signal
Command value call-ups [4]

Bosch Rexroth VT-VSPA2-1-2X/V0/T5 Specifications

General

Brand	Bosch
Model	Rexroth VT-VSPA2-1-2X/V0/T5
Category	Amplifier
Language	English