CAN Newsletter December 2008
| Business | Third CAN conference in Poland 6 French CANopen Days 16 French distributor 87 |
|---|---|
| Application | Rotary table controls communication 8 Controller system for railway vehicles 12 In-vehicle networks simulation 20 CANopen and Profibus combined 29 Programmable power supply for high-vacuum pumps 32 Car simulation with six axes 36 CANopen in X-ray systems 55 CANopen and robotics in medical applications 60 DSPs in medical electronics 64 Modular lithotripter with embedded CANopen 68 Sand machines for the finishing touch 70 Electrical drives for unmanned vehicles 74 Electronic display system for food outgo lines 78 |
| Device | Passenger information system for public transportation 10 Devices for trains and rail vehicles 14 Correction - GSM-R and GPS - I/O modules 16 CNC platform flexibility and economy with CANopen 18 Generic HMI - CAN Festival - Stepper motor unit 34 Inclinometers with MEMS sensors 38 General-purpose electronic control unit 76 Wireless sensor - Industrial controller - Display 88 |
| Tools | CAN/CANopen - For medical devices - Physical layer 66 Maintenance and diagnostics for redundant CANopen 84 Linux OS for infotainment 88 |
| Semiconductor | Controlling automotive body and chassis 72 Driver assistance systems and CAN communication 80 Small 32-bit MCU with CAN on-chip 82 |
| Reader service | CAN Newsletter subscription form 92 |
| Supplement | Too many candidates - Ethercat training 1 Redundant network layout for Powerlink 2 Powerlink - Ethercat 5 Safe PLC - Frequency inverter - Open Source - Encoder 6 Interface module - Bridge terminal - EPSG plug fest 7 CANopen application layer for Safetynet p 8 Ethercat product supporting CiA 402 10 CANopen mapping on Varan 11 Cog-free linear motion control 14 Powerlink controller and servo drives 16 |
Rotary table controls communication
- Fig. 1: Rotary table with processing stations, connection to supervisory control via CANopen and slip ring
- Fig. 2: Schematic view from top. Each process station performs its steps according to the table’s position
Helmut Ritter (Bachmann Electronic)
A customer from Bachmann Electronic creates a stretch blow machine for the extrusion of plastic bottles. The central mechanical part is a rotary table, which is equipped with a variable amount of processing stations. The preforms are supplied to the rotary table. The processing station on the table takes over the preform, applies it to a mould, stretches the preform with a servo drive and extrudes it with compressed air. Other mechanical parts of the machine for heating the preforms, supplying the preforms to the table and removing the finished bottles from the table, are static mechanical parts.
CAN has proven to be the most robust and efficient network to exchange process data between the supervisory control and the processing stations on the rotary table, as this bus system is ideally featured to be transmitted by a contact ring. The flexible configuration of a variable amount of process stations on each machine is eased by the usage of CANopen concepts.
While each processing station on the rotary table runs independently with the same programmed functionality, it needs to know the exact current position of the table to start the process after closing the mould. A supervisory controller system requires the position information to synchronize the handling of preforms and bottles. It also requires status information of each processing station. Moreover, for reasons of quality control some additional measured values for each bottle have to be transmitted to the supervisory control. For example, the pressure drop in a bottle can indicate a bad part, so that the bottle has to be sorted out from the process.
As the process time for a bottle is given, the throughput of the machine can only be improved by increasing the amount of processing stations on the table. To meet different customer’s requirements the concept had to be modular and had to support certain amounts of processing stations on each machine.
Some parts of the process are controlled mechanically, like closing and opening the mould. Software closed-loop regulators running locally on the processing stations control other parameters of the process, such as stretching and inflating.
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info@bachmann.info
Controller system for railway vehicles
Dan Staneasa (SC Tehmin-Brasov)
The SC Tehmin-Brasov company located in Brasov (Romania) has been asked to provide a command and diagnose system for S900 type railcars, which are currently under a modernization process.
S900 type railcars have two axles, two driver cabs and are capable to transport up to 64 passengers on regional lines with a maximum speed of 70 km/h. They were built starting with nineteen-thirties. During the years they have faced a lot of modifications. In the beginning the car body was made from wood.
The actual modernization process is involving the replacing of the old diesel engines and gearboxes of the vehicle. Consequently, a new electrical installation has been required.
The command and diagnose system has to perform:
- Starting and stopping of the diesel engine
- Control of the diesel engine’s speed
- Control of the railcar’s direction reversing
- Control of the lighting and sanding
- Collecting speed information from speedometer
- Displaying of different parameters for the driver (diesel engine’s speed, current gear attained by transmission, battery voltage, battery’s charging/discharging current, transmission oil temperature, etc.)
- Diagnose for the diesel engine and other railcar’s systems
Technical solution
In order to achieve that up to four such railcars are driven by a single driver, a train bus communication has been required, for linking all the railcars on a train.
The company has developed the entirely software application and redesigned the entire electrical installation. Also a new electrical cabinet for installing all equipments required by the control system was built. For implementing of the control system the MAS‑T PLCs (programmable logic controller) from Selectron Systems and MMIs (human machine interface) from RM Michaelides are used. CAN with the higher-layer protocol CANopen is used as the interconnecting vehicle network. This network comprises a CPU (central processing unit), acting as an NMT master, followed by DIO and AI extension modules, two MMIs, a CPU acting as a CANopen/J1939 gateway and the train bus gateway. The CANopen network is working at a bit-rate of 250 kbit/s.
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www.tehmin.ro
Configuration via Internet
Wieland Electric has extended its ricos TP PLC module with an integrated web server. This enables configuration of the CANopen network settings. In addition, a CANopen NMT slave function is implemented. They are designed for rough environmental conditions and are robust with regard to vibrations and operating temperatures (-40 °C to 70 °C). They are used mainly in rail-vehicle, and other outdoor applications. The devices meet the requirements of German Lloyd (GL), category C, and the so-called ”railway standard” (EN 50155). In trains, streetcars and subways the devices control and monitor the lights, the heating and ventilation, the doors, the loud speakers as well as the engines and brakes. They feature noise immunity of 20 V/m (according to EN 50121).
www.wieland-electric.com
