Digital Single Axis Controller
The concept of intelligent hydraulic drive – a vision?
"Sensitive" robotic steering
The operations cockpit not only provides the doctor with visual inform- ation but also moving information directly from the tool as it operates.
The operator sits a long way away from the robot on a HEXAMOVE platform providing six levels of movement. Speeds can be judged more accurately and cumulative vibrations can indicate areas of danger. This means that telemetric robot control becomes much more sensitive.
DSAC
(Digital Single Axis Controller)
Do you need hydraulic servo drive for your machine/system?
What would it be like if this drive system came with enough intelligence to be able to take over most of the configuration and optimisation work for you when you install it.
Wouldn't it be great if you hardly had to touch all the different individual components like servo valve, output setting, sensor system etc. any more? You could just close your notebook and the axis would "talk" to you via a communication programme.
It would just be a case of Plug and Play! And if anything did go wrong the drive system would also tell you why it wasn't able to do what you wanted it to do.
That's what the engineering team at OHE mean when they talk about an intelligent hydraulic drive system! Our development eff- orts are focused on achieving precisely that and the DSAC product can already give you some aspects of this vision today!
As the prices of microprocessors continue to fall this will mean that in future practically every component will have built-in intelligence. This means it's now time to take advantage of the enormous opportunities resulting from this.
Application Example 1
Hardware
Electronic modules
DSAC adapts itself to your requirements. The main printed board assembly already contains all basic functions. A plug socket for an addit- ional module offers further interfaces or extra I /O signals. At the heart of this is a Motorola processor, which is programmed in C meaning that it can also guarantee a real-time capabil- ity for dynamic hydraulic drive systems. The main printed board assembly already contains an on-board electronic evaluation function for a capacitive position sensor system. Other route measuring system can be connected to this via analogue interfaces or via the SSI or incremental input. The power output setting can directly control both the servo and pro- portional valves. Additional analogue ports mean that the valve control circuit can also be closed using the DSAC.
Space requirements
The DSACcan be installed where it is required within the system layout and where the intelligence is really needed. A simple base board or a housing with a DIN bar cover can be used to install the drive system as a unit.
The electronics can also, however, be integrated within the processor environment or even in the drive system. A stable metallic housing can be used here to protect all sensitive components from outside influences.
Interfaces
It is possible to communicate with the DSAC via a field bus module, or conventionally using freely programmable digital and analogue signals.
The parametrisation is provided by DSAC setup software with a windows front-end or via a simple hyperterminal. Access is via an RS232interface and a special cable.
All communication, analogue and digital signals can be combined within one interface cable. The electricity supply and power output to the valve is transmitted along separate cables.
Oscillates like a clock mechanism
This oscillating drive system has an integrated sinus gener- ator and an automatic amplitude adjustment feature.
The two parameter signals (target amplitude, target frequency) can be set continuously and smoothly.
A load weighing several tons will oscillate easily and exactly at up to 12 Hz and 50 mm of lift.
Application Example 2
The Windows program DSAC-Setup is available for the DSAC. The program clearly displays all information about the electronic system on the screen and allows you to set a large number of parameters.
Your notebook or PC is connected to the electronic system via a serial connection cable (see accessories).
You can then start the program and all parameters will be automatically transferred by the electronic system to the DSAC-Setup application.
This program allows you to set and configure control structures very easily. Current signal flow diagrams are clearly displayed in a clear. The program window for the functions is subdivided using different index cards so that the necessary parameters and functions can be found immediately. Here, any changes to the settings immediately come into effect and can be easily checked. If you are happy with the settings you can then instruct the system to load the parameters into EEPROM, meaning that they will be immediately avail- able even after the electronic system has been switched off.
Here, DSAC offers two separate control circuits that can be set individually. A separate index card is ava- ilable for both control circuits that lists all the parameters associated with each one. It is particularly easy to select the signal sources. For example you simply select from this list a channel that will be used to access the target value. This can be provided, for example, in analogue form via one of the analogue ports or can be an internal signal generator (e.g. Sinus, right-angle, etc.). A similar list is also available for the current value and for the controller output.For
example, the controller output can be accessed at the integrated output setting, at any analogue output or also at the input of the second control circuit (cascade control).
Other valuable functions are available in addition to the controllers. Analogue inputs can be aligned using the index card and the input can be set for an SSI or an incremental position sensor system.
Further menus allow the user to display the status of the interfaces online or even to initiate a small sensor data processing procedure. Fault diagnosis functions help you to systematically pinpoint faults in the controller axis and thereby save valuable time. Digital inputs and outputs can also be used to provide SPS functionality. This opens up a vast number of new possibilities for transferring the intelligence in a decentralized way to the driver axis because route valves, security elements and other components can also be incorporated.
With a large number of other functions the small and compact electronic printed board assembly becomes an intelligent controller axis with a performance that you will find impressive. You can obtain the latest information by downloading the full product documentation from the Internet (www.ohe.ch).
DSAC Software Setup
The simple way to configure your axis
Power or position control?
This cylinder drive system does both. Any starting position is initiated in the position control circuit via an integrated position sensor. The switch to power control can be activated manually or in relation to the load. The power measurement level between the piston and the tool measures the exact load for the power control
Application Example 3
It makes proportional hydraulics easier than ever before!
Digital axis controller for hydraulics with
integrated output setting and electronic sensor system
The DSAC axis module (Digital Single Axis Controller) is much more than a simple controller. The product integrates all the necessary electronic and software components on a single board. At the heart of this is a digital controller with a real-time system. The integrated electronics for the position sensor systems,
the power output setting for a wide range of contin- uous valves and other interfaces turn your hydraulic cylinder into an intelligent drive axis. You can obtain a detailed product description from the Internet by logging onto www.ohe.ch.
Microprocessor Motorola MC68332
Controller control circuit time 1 ms (positioning, steering and control, output setting value) Analogue inputs +/- 10 V DC (Single Ended or Differential) or 4 ... 20 mA Resolution of inputs 12 Bit (16 Bit on request)
Analogue outputs +/- 10 V DC (12 Bit)
Supply voltage + 24 V DC
Bus connections (optional) CAN, INFO-Link, Profibus, Interbus, DeviceNet (see documentation) Printed board assembly EMV-compatible version, SMD system
Interfaces (Standard)
Inputs:
A/D 0 Internal hydraulic cylinder position sensor system (KMS)
A/D 1 Target value display
A/D 2 Open (e.g. signal from slide position prop. valve)
A/D 3 Open
Digital Input 0 Open
Digital Input 1 Open
Digital Input 2 Open (e.g. approve output setting)
Digital Input 3 Open (e.g. damping the control circuit boost) Outputs:
D/A 0 Open (e.g. current value output from position sensor)
D/A 1 Open
Digital Output 0 Open
Digital Output 1 Open (e.g. alarm signal for drag faults)
Digital Output 2 Open
Interfaces (optional)
Inputs:
Digital Input 4 Open
Digital Input 5 Open
Digital Input 6 Open
SSI-Input or Input for SSI position sensor system
Incremental sensor Input Input for OS position sensor system, revolution sensor or other, Digital Input 1 Incremental position sensor systems (counter frequency max. 1 MHz).
Outputs:
Digital Output 3 Open
Digital Output 4 Open
Digital Output 5 Open
Digital Output 6 Open
Notes: – The digital inputs 5 and 6 can also be configured as outputs if required.
– If the position sensor system input (SSI or Incremental sensor) is not used, three other channels are available (input or outputs). These may be configured individually as a TTL/RS422 or a 24 V DC interface if required.
Oelhydraulik Hagenbuch AG Rischring 1/Postfach CH-6031 Ebikon/LU Tel. +41 (0)41 440 32 33 Fax +41 (0)41 440 32 85 E-Mail [email protected] www.hagenbuch.ch www.ohe.ch
DSAC – Ordering information
Type codes
The type code is made up of the basic printed board assembly and any additional printed board assembly as specified in the "extensions" category that can be connected to the main electronic system. The additional printed board assembly is necessary if you want to use an SSI position sensor system or incremental sensors or if you sim- ply require more digital interfaces.
DSAC – Zubehörteile
RS232 connecting cable for connecting PC/Notebook and DSAC 22.5000.0020 (standard cable)
Aluminium housing for DSAC for mounting on hydraulic cylinder 22.5000.0050 (without additional printed board assembly)
22.5000.0040 (with additional printed board assembly)
Housing cover with DIN35 bar snap-on unit 22.5000.0060
DSAC setup software 22.5990.0000
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