Functional Description 6 And - REXROTH VT-HACD-3-2 Series Manual

6/16 Bosch Rexroth AG Hydraulics
Functional description
The VT-HACD-3-2X closed-loop control electronics is a mod-
ule that is installed on a top hat rail.
A microcontroller controls the entire process, makes adjust-
ments, establishes links and realizes the closed control loops.
Data for configuration, command values and parameters are
stored in a FLASH in a non-volatile form.
The entire configuration and the parameterization and diag-
nosis are carried out via the BODAC PC program. Apart from
the switches for the address setting, the module does not
contain any other hardware switches. For the configuration,
the HACD has to be connected to a PC via a serial interface
(RS 232, 1:1 cable).
The configuration and thus the creation of applications are
very simple - you just have to link pre-defined functional com-
ponents. For this purpose, no programming knowledge is
necessary.
One mode is available:
• Structural editor
Own motion sequences can be created. For this purpose,
32 blocks are available. Each block contains: Command
value, ramp times (velocity ±, acceleration ±) and controller
parameters.
Blocks are activated by setting trigger conditions: Set-
ting digital inputs, comparing signals with freely definable
thresholds or expiry of waiting periods.
Signal links [6] [8] [17]
The HACD offers numerous possibilities for linking signals on
the input and on the output side, whereas it is in each case
possible to link 2 signals. This includes functions like addition,
subtraction, multiplication, division as well as minimum/maxi-
mum value generator, area ratio and limiter:
+ = Addition: Z = X + Y
– = Subtraction: Z = X – Y
* = Multiplication: Z = X * Y / 100
/ = Division: Z = X / Y * 100
MIN = Minimum value generator: Z = MIN (X, Y)
MAX = Maximum value generator: Z = MAX (X, Y)
RATIO = Entry of a ratio:
for RATIO >1: Z = X * RATIO – Y
for RATIO <1: Z = X – Y / RATIO
(e.g. area ratio with pressure differential measurement)
LIMIT = Signal limiter: Z = MIN (|X|, |Y|) * sign (X)
JUMP = Jump generator: Z = MAX (|X|, |Y|) * sign (X)
with Z ... Result
X ... 1st signal
X ... 2nd signal
T1 Lag = Low-pass filter
VT-HACD-3-2X RE 30543/12.10
Analog I/O [1] [15]
For the 6 analog inputs, you can switch between ±10 V,
0...10 V, 0...20 mA by means of the software.
For the analog output AO1, you can switch between ±10 V,
0...10 V, 0...20 mA and 4...20 mA by means of the software.
AO2 and AO3 are fixedly set to ±10 V.
The switching is performed by utilizing the whole range of the
analog-digital converter.
For all analog inputs, working range and error detection can
be defined.
The analog outputs can be adjusted by means of amplifica-
tion and offset.
Digital I/O [3] [16]
The HACD has 9 digital inputs and 8 digital outputs.
An input has the fix functionality Release, a digital output the
fixed functionality OK.
The other digital inputs are used for triggering blocks (see
blocks and triggering).
The function of each digital output can be determined by
means of selection from a pre-defined list:
• Command value = Actual value
• Actual value larger or smaller than an adjustable threshold
• Waiting period expired
• Ramp active
• Internal flag set
• Error flag set
• Table ended
• Error status
• Block timeout
• Controller active
• Absolute value (actual value) < window
• Absolute value (command value) < window
• Incremental home position
[ ] = Assignment to the block diagram on page 8/9