- Measurement electronics for EnDat 2.2
- For absolute encoders
- Ideal extension for machine tools
Position value acquisition
Measurement electronics for EnDat 2.2
With ADDI-DATA measurement solutions you can connect up to 8 EnDat 2.2 encoders and acquire the position values of absolute encoders. In combination with the digital bidirectional interface EnDat 2.2 absolute encoders provide the position value directly, without reference run. EnDat 2.2 is preferentially used for applications with highly precise positioning and high repeat accuracy. Diagnostic data like temperature, line break, etc. can also be transferred.
More and more, measurement devices and machine tools transfer position data through EnDat 2.2 interfaces to the subsequent electronics. This helps the engine builders to increase the machines’ productivity and to improve the competitive ability of the devices in which the machines are integrated.
To guarantee a reliable classification of the position value even in case of long lines, EnDat 2.2 features signal delay-time compensation. At the start of the positioning process, the time for each cycle until the response of the EnDat 2.2 data package is acquired.
As additional data like for example temperature values can be sent, it is possible to effect corrections in the process quickly in order to guarantee a constant accuracy during the positioning process. This is important for small production lots or in case of different use of tools.
EnDat 2.2 is a bidirectional synchronous-serial interface for position measurement devices. This interface allows to read out absolute position values and parameters, to write status and initialisation registers and to transfer additional information about the position value. In addition, ADDI-DATA EnDat 2.2 solutions support the evaluation of diagnostic values and access to the OEM memory. Data is transferred serially.
• Fast data transfer, frequency depends on the subsequent electronics
• Signal delay time compensation
• High contour accuracy
• High transmission safety
• No need for additional sensors: Evaluation (temperature, limit switch, etc.)
• Serial transmission: only 4 lines necessary
• Single-line wiring (M12, 8-pin)
• Automatic parameterisation through electronic type plate
High requirements for the subsequent electronics
Whether PC-based or distributed – the EnDat 2.2 interface has high requirements to the subsequent electronics: Precise position detection at high frequency, velocity, robustness and interference-resistance are significant for the subsequent electronics.
ADDI-DATA offers four different solutions for the position acquisition:
• PCI-Express counter board with a high input frequency up to 10 MHz (optional)
• Intelligent motion control board for complex positioning tasks
• Intelligent Ethernet counter system for direct use inside machines
• Motion Box for real-time positioning tasks
Functional principle
Application example
Exact positioning of axes for the regulation of surface measurement devices for
rotationally symmetric parts (e.g. gear wheels)
Challenge:
For the measurement of the surfaces of rotationally symmetric parts numerous axes must be positioned. Furthermore the signals must be fastly transferred in order to detect the position as exactly as possible. To safe time, absolute encoders are used because they do not need any reference runs when started.
Solution:
The measurement device consists of a measurement table with a gate. The rotationally symmetric parts are fixed on the measurement table and their surface is tested with a sensor connected to the gate. To move the sensor around the parts the gate has several axes equipped with EnDat 2.2 absolute encoders. The precision of the axis position is assured by the PCI Express counter board APCIe-1711: Thanks to its high input speed of 10 MHz (optional APCIe-1711-10MHZ version) and its resistance to interferences, the board is able to move the axes precisely even at high speed.
Position acquisition of glass components at a welding process
Challenge:
For the construction of glass components two parts are welded with hot air. As the material is very fragile the welding process must be carried out very carefully and precisely (1 µm) despite of the speed in order to avoid the breaking of the parts. Furthermore it must be made sure that the glass components are close enough to guarantee a good quality of the weld seam. Thus the position of the component shall be acquired in intervals of 200 ms.
Solution:
For the position detection of the glass components the Ethernet counter system MSX-E1731 with EnDat 2.2 sensors has been chosen due to its speed and precision. At the beginning of the welding process the SPS triggers the MSX-E1731 system to start the measurement process. As soon as the glass components are in the correct position the system sends two signals: One for the digital output to stop the axes and via Ethernet the start signal for the welding process. When the welding phase is over all acquired data is transferred to a Linux server for archival storage.
Automatic measurement device for clutch disks
Challenge:
The functional reliability of the pull-back springs on clutch disks shall be tested. Thereby the force in relation to the distance shall be measured. How can the relation force / distance be exactly established?
Solution:
For establishing correctly the relation force / distance, position acquisition plays an important role. A clutch disc is positioned and locked in place on a conveyor belt. A plunger gets down until it reaches the clutch disc. The plunger turns and thereby force and distance are measured. In order to find the absolute positions as fast and as accurately as possible, EnDat 2.2 encoders are used for the positioning of the axes. An APCI-8008 board acquires data from the EnDat 2.2 encoders and the position values are included in the regulating process. To get the force values, the APCI-8008 reads the measured values of the PCI pressure measurement board APCI-3300 directly via bus master access.
EnDat 2.2 Measurement electronics
PC-based and distributed solutions
Counter board PCI-Express
• Fast counter inputs (up to 10 MHz)
• Can be combined with functions like PWM, incremental
• 64-bit drivers for Windows 7/Vista/XP
Intelligent motion control board
• Controling up to 8 axes
• Mixed mode servo / stepper motors
• Ethernet/EtherCAT interfaces
Intelligent Ethernet counter system
• 4 counter inputs
• Direct sensor connection
• For use in the field, IP 65
Customized solutions
The best solution often is customized. As a manufacturer, we are able to adapt our solutions as closely as possible to your requirements.
We are pleased to advise you on finding the best solution for your applications and to perform the necessary adaptations for you.
Just ask us!
