Abstract: This paper describes optical characteristics of a single CAN network and the lack of work. CAN network to improve the survivability of optical fiber, optical fiber CAN bus design self-healing network. Plastic manner (POF) for the transmission medium, with a wavelength of 650nm red laser optical transceiver device of an optical / electrical conversion. Analysis of the CAN network data frame structure, it presents an interface circuit based on CPLD realization of self-healing methods. Vehicle CAN bus through the formation of self-healing fiber optic network that the network not only has the self-healing function, but also to eliminate fiber optic ring network CAN obstruction.

CAN bus is a German company Bosch 80 in the early 20th century to solve the vehicle developed a number of data exchange a serial data communication protocol. Because of its excellent properties, CAN bus become recognized some of the most promising one field bus. CAN bus transmission medium can be twisted pair, fiber optic and coaxial cable. Twisted-pair CAN bus has now been widely used, the technology has matured. Twisted-pair CAN network technology in the easy, low cost, and electromagnetic radiation on the environment have a certain immunity. But when the work environment particularly complex, its anti-interference ability is not very satisfactory. If electric vehicles on site, the situation is more complex, car electrical system will produce strong electromagnetic interference, will lead to twisted-pair CAN networks can not function properly. Compared with the twisted pair and coaxial cable, fiber superior performance - a strong anti-EMI ability to attract attention. To further enhance the performance of CAN networks should be used to make optical fiber transmission medium. As the vehicle local area network transmission distance is short, while optical CAN network in order to reduce the cost of car may make use of plastic optical fiber (POF) as a transmission medium. Plastic optical fiber transmission in high-speed short-distance communication in low cost, easy connection to bypass good, light weight, so networking and low cost. Germany's BMW in March 2002 listing of the most advanced new car "BMW7 series''used to build the car at 50m POF LAN.

CAN network of optical fiber as a low-level control of industrial local area network, its topology and used the same local area network, the basic topological structure of the bus-shaped, circular and halo shape. Single-loop fiber-optic network in the CAN, because of the delay devices will lead to loop the signal from the shock, so that ring CAN network congestion (or locked). CAN bus controller to comply with the agreement in the link layer should be to design a single fiber optic ring network CAN dedicated logic control unit LCU. The unit's functions are: implementation of the CAN bus data transceiver control, that is the master node does not forward the received data, when the data along the fiber loop back to the original sending node, he was immediately removed; from the node forwarding the received data. Can also eliminate ring fiber CAN bus network, the phenomenon of self-excitation to ensure that rings are not blocked.

Q single-loop fiber-optic network, node or network link failure may cause paralysis. In order to improve the survivability of fiber optic ring network, should constitute a self-healing function of self-healing fiber optic loop network.

A fiber-optic self-healing ring network design CAN

1.1 Structure of optical self-healing ring

CAN fiber optic self-healing ring network shown in Figure 1. The network has two fiber optic loop - clockwise and counterclockwise ring ring, each node SJAl000 CAN controller interface circuit and the loop through the fiber optic network connected to interface circuits produced by the Altera Corporation's complex programmable logic device (CPLD) EPM7128S The two optical transmitter LEDR and LEDL, two optical receivers PINR and PINL composition.

1.2 Interface Circuit Function

CAN Network Interface Circuit fiber self-healing features are: (1) When normal communication optical fiber loop (Figure 2 (a) below), each node in the right end of the left side optical transmitter LEDR send data PINL optical receiver, signal clockwise transmission; Similarly LEDL PINR data transmission, signal transmission counterclockwise, or choose the opposite transmitter data forwarding. (2) When a single fiber failure (Figure 2 (b) below), the downstream C node interface circuit loop, because the left side of optical receiver PINL no signal, right end of the optical transmitter LEDR choose the same side optical receiver PINR data forwarding. (3) When any node between the two fiber failure (Figure 2 (c) so), such as BC optical fiber between nodes is cut off, then B, C and fiber cut off point of two nodes connected to the implementation of loop-back function. At this point, the signal from A to C, AC is the first by a clockwise loop to B, via counterclockwise loop through A, D arrived C. The signal CA will still be transmitted by a clockwise loop. This self-healing function under fault conditions to ensure the continuity of ring can be maintained. After troubleshooting, switching automatically switches back to the original location. (4) CAN controller data to achieve the node chooses to receive. The principles are: for each node to receive the smooth, counterclockwise data, select PINL, PINR the first to reach the data reception. (5) to achieve the node data select Send. The principle: when the bus is idle, select the node transmitter TX CAN controller to send data, remove the ring fiber CAN bus network, the phenomenon of self-excitation to ensure that rings are not blocked; when the CAN controller of the node to receive node , select the data to send the opposite; when the CAN controller node to receive node, and the contralateral Fibre Channel fault, then select the same side of the data to send. (6) determine the channel frame start and frame end, differential bus is idle, the network is fault. Such as the receiver judge to left metering data frame is transmitted PINL have produced when the left side to send data and network communications status symbol flag_l logo sync_l.

2 interface circuit design

Self-healing network self-healing fiber optic CAN transceiver control function and the programmable logic device (ALTERA EPM7128SLC84 1 15) implementation, programming using VHDL language. A concrete description below.

2.1 input and output port settings

Figure 3 shows the interface circuit CPLD's I / O port diagram. Among them, the input and output pin_l, led_l, 1ed_r, pin_r respectively with light / power conversion module PINL, LEDL, LEDR, PINR connected: txd, rxd each device with the data system CAN Jing sender TX, RX receiver is connected; flag_txd = 1 CAN controller TX0 on behalf of the node is sending data frames; flag_l = 1 channel is sending data on behalf of the left frame; flag__r = 1 channel is sending the right documents on behalf of the frame. sync_l status symbol for the left side of network communications, sync_r status symbol for the right of the network traffic. When the left channel is normal, the output sync_1 = "l", driven network status light emitting diode D_sl; when the right channel is normal, the output sync_r = "1", drive network status light emitting diode D_sr; if the network status light-emitting diode D_sr or D_sl off, that corresponds to Fibre Channel network out of trouble. When the node select the left channel CAN controller, the data received, the output side rx_l / r is high; when the node select the right channel CAN controller, the data received, the output side rx_l / r is low. Reset for the reset input terminal, active-low; clk0 for the clock input, input clock frequency of 20MHz.

Self-healing fiber optic network of CAN bus

2.2 CPLD functional structure

CPLD to control the self-healing ring network interface unit, the control circuit consists of a divider, a central state machine, send data selector, data selector receiving the composition, shown in Figure 4.

2.3 Crossover

Communication Interface CPLD clock frequency 20MHz. CAN self-healing fiber optic network in each node and CPLD Interface CAN controller SJAl000 work with independent clocks. In order to produce the flag state machine signals synchronized with the CAN controller, data transfer, to ensure the two data selector switch and data synchronization, should be the correct choice of the state machine clock. This network of data transmission in the CAN baud rate is 125kbit / s, the state. Machine clock rxclk design data transfer rate of 8 times the baud rate, that is 1Mbit / s, to ensure the data bits in a CAN data read cycle can be repeated to improve anti-jamming capability. So divider function to generate a clock frequency of 1MHz.

2.4 The state machine center

Based on CAN 2.0B protocol, CAN network data frame consists of seven different bit fields, namely SOF, arbitration field, control field, data field, CRC field, response field, the end frame. Data field length of 0 to 8 bytes. Frame start position is a dominant bit low power? Quot; 0 "; frame end of the 7 recessive bits from" 1 "consisting of sequences; in the data frame transmission, the use of digital technology add charge coding, to ensure data frame bits stream will not be five consecutive "1''or''0."

Central control state machine is the design of the core modules. Center of the state machine functions are: (1), the detection frame CAN data frame start and end frame, producing a corresponding signal to send data flag flag_txd, flag_r and flag_l. (2) generation network communication status flags sync_r and sync_l. Center by the state machine: the composition of the three state machines: the CAN controller state machine node, the left channel and right channel state machine state machine. They were discriminant each channel (TX, PIN_L and PIN_R) whether there is data transfer. The following explanation of the different parts of the state machine are the nodes in CAN controller state machine as an example.

Self-healing fiber optic network of CAN bus

The state machine sets the 61 states, that is idle, S1, S2, S3 ... S60. When the bus is idle, the state machine is in idle state idle, then come along rxclk the detected txd = 0, the state machine turned to S1, while the data flag is set to send the signal flag_txd = "1"; the second upper edge, the state machine unconditional turning S2; third on along, the state machine unconditional turning S3; fourth on along, the state machine unconditional turning S4; fifth on coming along, the point is the central location of data bits, data stability, read the data again, if txd = "0" is still set up the conditions that frame start coming, the state machine turned S5; otherwise flag_txd = "0", while state machine turned idle state idle, waiting for the arrival of the start frame.

When the state machine is in S5, the then rxclk (1MHz) than one for each clock cycle, state machine state prior to further (S6, S7, S8, S9, S10, S11, S12, ... ..., S58, S59, S60); Every 8 clock cycles, on the CAN bus data bits to a detected (S12, S20, S28, S36, S44, S52, S60), ensure that each test in the data bit (bit period) Central. When the continuous 7 txd = "1", the detected "1" means "the end of''the arrival of the frame, sending data flag reset flag_txd =" 0 ", waiting for the arrival of the next frame start; otherwise the state machine returns the state S5, waiting for the arrival of the end frame.

Network communication status sync_r, sync _l is for an important basis for self-healing ring network. As mentioned above, when the channel to send data about the state flag flag = "1''when the network communication state of the channel sync =" 1 ", the network status light-emitting diode D_sr, D_sl light; when the frame when the end came, flag =" 0 " to start the network communication state count group count, the clock is rxclk = 1MHz, when the counter is 30000, (30ms), sync = "0", the network status light-emitting diode D_sr, D_sl off. This means that a data frame, if re- no other data were also detected in the starting frame, the network broke down. If Zai Dao can be detected within 30ms data frame 起始 (flag set Wei), the network communication Zhuangtai logo sync continued to "1". counter reaches the full value of Shi Jian The frame should be the shortest time interval estimation.

2.5 Data Selector

Send data and receive data selector selector function is to achieve link structures (that is, channel selection). To ensure the network to work, CAN network delay should be less than a data width (bit period). To link structure of time as short as possible, using the maximum clock frequency (20MHz) control of two data selector.

Sending the data selector, CPLD testing three-way channel data txd, pin_l, pin_r. The channel data with different priorities. Priority setting: When the node to send data (txd = "0" or flag_txd = "1''), the left and right channel to send control tanning ⑺ CAN vote Tang X data, which led_r = txd, led_l = txd. If This node does not send data, according to sync_r and sync_l choose to send data, were normal when the left and right channel, select the opposite data transmission, led_r = pin_l, led_l = pin_r. If a channel fails, the data not to see the opposite side, select the This side of the data is sent, led_l = pin_l, led_r = pin_r. Accordingly, not only to achieve self-healing network, but also eliminates the ring network blocking problem.

Self-healing fiber optic network of CAN bus

In the receive data selector, set the left channel as the preferred receive channels; not yet reached the time when the left channel data (flag_l = "0'') or the left channel failure, without human intervention, automatically selects the right channel to receive. Accordingly, achieve optimal reception (choice of priorities to reach channel data reception), and double-loop fiber CAN bus network self-healing capabilities.

Formed in the electric vehicle CAN self-healing fiber optic network, using plastic optical fiber as the transmission medium, plastic optical fiber has low loss window in the visible region, selected wavelength of 650nm (red) optical / electrical converter module - Agilent produced HFBR-1528 optical transmitter and optical receiver HFBR - 2528. CAN nodes control discharge device or with optional SJAl000 TMS320LF2407 DSP chip CAN controller, composed of four CAN self-healing optical network node board. CAN network data transfer rate is set to 125kbit / s, when the failure to set a certain channel, the network can achieve Figure 2 (b) are not self-healing function; when setting any node failure between the two fiber-optic network to Implementation Figure 2 (c) shows the self-healing capabilities. When the CAN node fails, the interface circuit can still work to ensure loop network; when the interface circuit failure will cause the node from the bus, the other nodes to achieve network self-healing, constitute a single ring. Through the oscilloscope to observe, sending node to send data through the bus competition; receiving node can send a response signal to the bus; node data through the 4-node self-healing fiber optic CAN return nodes in less than 100ns. After testing, the channel failure time for self-healing network 301ms

1.485 bus, what kind of communication should be used line? A number of bus devices can be attached?

RVSP shielded twisted pair must be used. Shielded twisted pair used for specification, communication lines with the 485 distance and the number of devices attached on the following table. Shielded twisted pair helps reduce and eliminate the two 485 lines and the distributed capacitance between the communication lines from around the resulting common-mode interference. The number of communication lines from the device communication standard 1-400m 1 - 32 units 0.5mm2 400-800m 1 - 16 units 0.5mm2 400-800m 17 - 32 units 0.75mm2 800-1200m 1 - 8 units 0.5mm2 800-1200m 9 - 21 units 0.75mm2 800-1200m 22 - 32 sets 1.0mm2 Contractors used by most cable or over Category 5 cable Category 5 as the 485 line, which is wrong. This is because: (1) does not shield ordinary network cable, can not prevent common mode interference. (2) cable is only 0.2mm square feet, the diameter is too small will result in reduced distance and reduced equipment can be attached. (3) network as the single strand of copper wire, compared to multi-core wire in terms of easy to break.

2. Why Ground

485 transceiver provides the common mode voltage between-7V to +12 V when to work properly. If you exceed this range will affect the communication, a serious damage to the communication interface. Common mode interference will increase the common mode voltage. Eliminate common mode interference is an effective means of communication line 485 as a ground shield, the equipment, computers and other network devices connected together, reliable access to the earth by one o'clock.

3. Electric Lock and controller / reader can use the same total power to the electricity?

Can not. Electric lock does not move in the case, SKPS ripple voltage is only 40-50mV; Once the action, that is, electronically controlled lock in opening and closing, the ripple voltage to rise to 100mV-300mV, the ripple will be passed to line into the controller and the reader, resulting in communications chips and CPU heat, resulting in communication instability, severe burn will chip. And electric power and power locks moment, electric control lock inside the coil, will produce a high charge and discharge pulse 850mA, if the electronic control both ends of the lock if there is no parallel diodes, the ripple signal will pass controller and card reader. A controller, and it recommended that all readers share the following mount a SKPS power; the controller electronically controlled lock each of the following each use a separate SKPS power.

4.485 lines of communication should be how to take the line?

Communication line as far as possible away from power lines, not parallel with the power cord, but not tied together.

5. Why are 485 structures to be used hand in hand, and not with star-shaped structure?

Star structure will produce the reflected signal, which affects 485. Bus to each terminal equipment branch line length should be short, usually not to exceed 5 meters. If you do not take the branch line of the terminal, there will be reflected signal, generated a strong interference on the communications, it should be removed. Access control system, there are two places applied to the 485 bus. First, mount the controller computer to the following, the second is mounted below the 485 controller to the reader.

6.485 device to device on the bus between the contacts can it?

In the same network, using the same cable, to minimize the contact lines. Contact Office to ensure a good weld, closely packed, to avoid loosening and oxidation. Ensure a single, continuous signal path as buses.

7. What is common mode and differential mode interference interference? How to eliminate the interference of the communication line?

485 line consists of two twisted-pair line formed by two lines of communication which is the voltage difference between the way to pass the signal, so called differential voltage transmission. Differential mode interference in transmission between two signal lines, belonging to the symmetry interference. Differential mode interference elimination method is to add a partial value of the circuit resistance, and a twisted pair; common mode interference is between the signal line and ground transport, a non-symmetric interference. Eliminate common mode interference include: (1) using shielded twisted pair and the effective ground (2) strong electric field of the areas we consider using galvanized pipe shield (3) away from the high voltage wiring, not to the high voltage power lines and alignment signal lines tied together (4) Do not share the same electric lock power supply (5), linear power supply or high-quality switching power supply (ripple disturbance is less than 50mV)

8. 485 under what circumstances to increase the termination resistors on the bus?

Under normal circumstances no additional termination resistors, only 485 more than 300 meters away from the case, to 485 the beginning of the end terminal resistance increases and the end client. In particular the 485 bus when there are fewer number of devices. When large number of devices (such as more than 22 units). Generally do not need to increase the terminal resistance, because the termination resistor will reduce the load capacity of 485. When the need to increase the termination resistors, as long as the controller above can set the terminal resistors jumper, if the other end is connected to the computer, then the converter 485 while the brown and white short-circuit.

9. How to extend the communication distance of 485

Specification is one of 485 network length of 1.2 km, 32 nodes. If you exceed this limit, then the hub must be used to expand the network of 485 distance or number of nodes. Using 485 hubs, 485 network can be divided into a large number of segments. Like the hub 485 between segments 485 "bridge." Of course, each segment 485, or follow the above specifications, the 1.2 km length and 32 nodes. Extend the network distance by 485 Hub Icon: the use of 485 485 fork hub to solve the problem, as shown: the use of the hub structure 485 Star 485 485 485 repeater hub is the Extension of the Concepts It not only solved the problem of multiple bifurcation, but also solve the problem of isolation between network segments, one segment that is a problem (such as short circuit, etc.), and will not affect other network segment, thereby greatly enhancing the large-scale network security and stability. We can see from the LAN to the star from the bus-based development process, to appreciate the star wiring network to our benefits. Likewise, the composition of the star hub 485 485 485 Network will also be a direction of network development.

CAN-BUS controller area network bus technology (Controller Area Network-BUS) has become a factor of category whether the vehicle is the "digital". In essence, CAN-BUS is a real-time data bus technology. Throughout the body through the sensor to the vehicle in the collection of a variety of information, do not give the address of the signal receiver, the sender can signal the security encoded data is sent to all recipients, prone to short frame way to achieve high real-time data; high-speed CAN-BUS can be sent every 32 milliseconds bytes of valid data, the receiver each signal read from the bus on their own the data they need. With CAN-bus can significantly reduce the use of wires, also reduced the relative number of the contact line, CAN-bus transmission speed according to their differences and then divided into high-speed (HSCAN), medium speed (MSCAN) and low-speed (LSCAN) network. In general, safety, handling of related computer architecture for high-speed network; associated with audio and air conditioning in the medium-speed networks; and are complementary with the phase in the low-speed network. And each network as a relay between the gate by a computer to exchange information. What is CAN-BUS, the image of that in the past after opening the engine, you can see a series of lines, all of these lines are now gone, is for the replacement of a fiber, if I cut it into two words, If you do not touch, you immediately can see the light, the transmission speed is very fast, it is natural to mention the cost is very high. You can think of, the traditional wiring harness car circuit by connecting electrical equipment, which requires a lot of lines, and these lines need to plastic packaging, plastic will be used for a long time after the aging process of the car in the exercise of the temperature is so high, Therefore, the plastic will break, it will have short circuit, the general use of one or two years more than three years when the car is not here, there is something wrong, they are actually wrong line, and now these lines into an optical fiber, first, When we open the hood, when only one optical fiber; Second, there is no line aging, no fault, short circuit phenomenon, but the cost is very high, basically we use the local area network control system. The more high-end CAN controller inside the car more, there are two, three, four, and of course not the same price, and now we see 25 million more than the price of the car have this thing, do not look down on this thing, In fact, it is a module that there are many switches, components, interfaces, and if you want to connect the two modules, when only that an optical fiber, so that transmission fast, no problem. In this example illustrates one of the most common vehicles in the current difference between the previous car: the traditional groups in the vehicle engine cooling water temperature sensor will inform the engine control computer, respectively, and the water table through the instrument panel tell the driver; in with CAN-bus is a vehicle to take a cooling water temperature sensor by the engine control computer converts the signal, and then sent to the instrument panel of the water table. In a traditional car, there will be an additional line from the cooling water temperature sensor received a dashboard to provide the information required for water table; However, in today's cars can reduce these unnecessary extra cables and connectors, thus reducing The fault may be generated. POLO CAN-BUS with Shanghai Volkswagen POLO popular car in the market, POLO cars on the configuration of many advanced technology and equipment, but also increasingly become the focus of consumer concern. CAN-BUS technology's biggest advantage is to reduce the number of the wiring harness and controller interface pins, at the same time can more easily and quickly to achieve on-line programming, online diagnosis and even more new features such as joint action controller . CAN-BUS technology in the communications node is a controller, intelligent sensors or smart execution unit, in the POLO vehicle, and only six communication nodes to replace the complex wiring harness, easy to achieve a full car data sharing. POLO data sharing for the entire vehicle into a car's overall intelligence, which has the self-regulation, for example, turn off the engine when the parking time, CAN-BUS type system will comfort dormant state of the system is in the low power to reduce energy consumption. Once received the door open signal, without starting the engine, the system wakes up immediately activated, the entire nodes started to accept the message, the vehicle adjust to the best working condition. Highly intelligent CAN-BUS technology, used in the POLO cars on the CAN-BUS technology, but also assume the same role. POLO cars equipped with the third generation of electronic anti-theft system (WFS-III), its advanced security design is based on CAN-BUS technology. First, make sure check the legality of key information through the CAN-BUS for delivery, improved encryption algorithm, the parity information than the previous anti-theft system is more abundant; Secondly, the car keys, security storage controller and engine controller each other information, can not be deciphered, to improve security. SEAT CAN-BUS Skoda Auto is the most "practical" typical models. Since the debut in the country, with its simple and smooth appearance, excellent safety performance and excellent value for money in the sales of imported cars dominate the market. It is particularly worth mentioning is that 04 Octavia series uses very advanced in Europe CAN-Bus system. In addition, 04 new Octavia is equipped with central door lock (through a door switch in the driver's seat, can control the whole car off and open the door of a control device, and with it even if the windows were broken and not after open the door from the outside into the car.) new intelligent key role in the anti-theft system, if not the correct password, even if the key is exactly the same shape after you start the engine, 3 seconds will automatically turn off. This technology, in its class is a rare Touran CAN-BUS from 2004 to 2005, the name China as a whole car scene is particularly bright, as people talk about the center of the topic. MPS put forward new ideas, people confined overnight MPV subvert the state, and to define a new utility vehicle standards. Both for the domestic automobile market, or for fans Touran is an exciting news. Touran 1.8T also combines advanced Bosch Motronic ME7.5, 32MHz electronic control system, can greatly reduce the mechanical loss of the engine is running, the engine in all operating conditions can have good fuel economy, achieved a small heart large output. In addition, Touran 1.8T also uses CAN-BUS bus LAN function, the power system with ABS, MSR, MASR system controller, the combination of instrumentation and automatic transmissions and other controllers connected to a larger power in the same time, they have a good the economy and handling, better meet the emissions requirements. Drive system, comfort and information systems of three sections. Given the address of the receiver signal, the signal sent by the security encoded data is sent to all recipients, high-speed CAN bus can be sent every millisecond 32 bytes of valid data, the receiver each signal read from the bus on their own whichever is the required data.

PROFIBUS: Introduction

PROFIBUS is not one communication system, but a variety of protocols built on the same field-bus technology bundle. Users can combine varieties of PROFIBUS protocols with their own software and other requirements, resulting in a unique application profile. With many profiles available, PROFIBUS can suit specific needs. One thing remains the same, though. Through thorough testing, PROFIBUS devices meet a high standard of quality befitting a high quality network.

History

PROFIBUS was born out of a combined push by the German government, German companies, and other industry leaders in the late 1980s. Their effort created an automation solution that is not only still viable today, but has led to further solutions. The proud heritage of PROFIBUS allows for many European customers to turn to automation specific to their needs.

Origin

In 1987, 21 companies and institutions in Germany joined forces to create a new protocol. Their goal was to create a bit-serial Fieldbus system. In order for the system to be viable, they needed to standardize the field device interface. The group, which had taken the name Central Association for the Electrical Industry (ZVEI), completed its goal with the creation of PROFIBUS FMS (Fieldbus Message Specification).

This new protocol satisfied standardization of Industrial Automation through a protocol capable of sending complex communications. The ZVEI was not finished, though. In 1993, the group introduced a new standard, PROFIBUS DP (Decentralized Periphery). This new version featured more simplicity, including easier configuration and faster messaging.

The ZVEI continues serving the electronics industry in Germany. Their work to create PROFIBUS was vital.

Organizations

PROFIBUS standards are maintained and advanced via a pair of important organizations. In 1989, PROFIBUS manufacturers and users created the PROFIBUS User Organization (PNO). This group was, and still is, a non-commercial venture. Members work to advance PROFIBUS through support and education, including publishing documents that help users satisfy their needs using existing technology.

A larger group was formed in 1995 and named PROFIBUS International, or PI. As the largest Fieldbus user association in the world, PI is able to undertake many tasks vital to the progression of PROFIBUS. Like the PNO, PI educates users on PROFIBUS and helps advance its placement throughout the world. The organization goes further, though, by helping with quality assurance, setting standards, and developing new PROFIBUS technologies.

Overview

PROFIBUS is a smart, field-bus technology. Devices on the system connect to a central line. Once connected, these devices can communicate information in an efficient manner, but can go beyond automation messages. PROFIBUS devices can also participate in self-diagnosis and connection diagnosis. At the most basic level, PROFIBUS benefits from superior design of its OSI layers and basic topology.

While Chinese banks are seeing a credit boom due to the nation's huge stimulus package, their foreign peers have not been so lucky and might just be facing their most difficult period as far as business expansion in China is concerned.

According to the central bank's latest monetary policy report, in the first half of 2009, lending by foreign financial institutions in China dropped by 32.7 billion yuan. This is in stark contrast to the recording-setting 7.37 trillion yuan in new loans that Chinese banks gave out in the same period.

Analysts said foreign banks in China, restrained by their global development strategy and disadvantages in competing with Chinese banks for funding major government-led projects, could see a significant decline in business revenue this year.

Foreign banks have rushed to extend their presence in the Chinese market since the nation fully opened up its banking industry in December 2006, but the unexpected global financial crisis, which badly hurt the banks' parent companies at home, has curbed their aggressive expansion spree in China.

"The main clients of foreign banks in China are foreign companies, whose demand for loans has shrunk significantly in the current economic downturn," Lian Ping, chief economist of Bank of Communications, said.

"On the other hand, major Chinese banks gained an upper hand in funding State-backed infrastructure projects, which are usually less risky than lending to companies and are not easily accessed by foreign lenders," he said.

State-controlled banks, main lenders to the government-led 4-trillion yuan stimulus package, advanced 3.26 trillion yuan in new loans in the first half of this year, accounting for nearly half of the nation's entire lending in the period, while foreign banks are commonly believed to be at a disadvantage in making such lending because they lack government connections.

"Chinese banks have natural advantages in that there is a strong government inference that State companies should park their deposits and seek loans from State banks," an industry source at a Shanghai-based foreign bank said.

After experiencing galloping growth in 2007, foreign banks saw their business expansion in China slowing significantly last year as a result of the global financial turmoil, with their total assets growing by just 13.2 percent, down 35.3 percentage points from a year earlier. Analysts said the situation could be even tougher this year.

"Besides the lending front, some companies have also started to shift their deposits to Chinese banks and more high-end individual customers are turning to Chinese banks for wealth management," Li said, adding such customer drift could be a short term phenomenon.

An earlier central bank report revealed that late last year, when the global financial crisis was in full swing, it was very difficult for foreign banks in China to get funds on the inter-bank market due to market concerns about the financial situation of their parent companies.

Major locally incorporated foreign banks HSBC (China) and Citibank (China) have declined to comment on their business operations this year, while Standard Chartered Bank (China) said it had not seen a major dent in its credit volume this year.

In contrast, analysts believed that Chinese banks could achieve decent growth for the whole of this year thanks to the lending spree in the first half, but remained vigilant on a possible bad loan surge next year.

China's policy on automotive joint ventures is expected to be loosened and the ceiling for foreign capital investing in joint ventures raised, the Economic Observer quoted an insider as saying.

"The shareholding structure for Sino-foreign automakers will likely be not that strictly restricted in the future as economic reform deepens," said Zhang Xiaoyu, executive vice chairman of the China Machinery Industry Federation, at a recent industry forum.

Currently, foreign automakers are not allowed to own more than 50 percent in their Chinese joint ventures. But some signs suggest the policy might be loosened.

Loosened policy

"More and more larger auto groups in China finance in the overseas capital market, so strictly speaking, the Chinese side also has overseas capital," said Zhang. "You can't say the Chinese side is purely domestic or State-owned assets."

According to China's automobile industry policy in 1994, in a Sino-foreign joint equity or cooperative venture producing whole automobiles, motorcycles or engines, the share of the Chinese side cannot be lower than 50 percent.

But in 2007, a supplemental provision on Sino-foreign motorcycle or engine companies was released, and under the provision shareholding proportions are not restricted.

"In addition to auto joint ventures, the whole auto industry is opening up," said Luo Zhongwei, an industry economics researcher with the Chinese Academy of Social Science.

Luo said that auto financing, one sector under stringent control, is opening up. At present, foreign companies can not only open auto financing companies in China, but also operate expanded businesses according under new management measures issued in January this year.

The country posted a trade surplus of $41.42 billion in the first quarter this year, down 10.8 percent from the same period of last year, dragged down by restless yuan appreciation and a likely economic recession around the world. However, Chinese commercial vehicle makers seemed unaffected.

"Although our specific figures for the first quarter haven't been released, our exports will definitely grow from last year," claimed Zhao Mei from Shaanxi Automobile Group's marketing department. SAIC-Iveco Hongyan Motor Co Ltd came with similar words.

Zhang Yikui, overseas marketing director of Anhui Jianghuai Automobile Co Ltd, disclosed that Jianghuai Auto exported more than 6,000 trucks between January and March this year, up 40 percent year on year. "Jianghuai Auto's export destinations are mostly in the Mid-east, north Africa, and the Persian Gulf areas, and little to Europe and North America. Orders from our clients are mostly stimulated by their own currencies' appreciation against a comparatively weak dollar," said Zhang.

New wastegate released by Turbonetics features Direct Flow Technology (DFT), an inconel 45mm valve, and cast stainless steel base capable of controlling 700+ HP.

Simi Valley, CA (PRWEB) May 30, 2008 -- New wastegate released by Turbonetics features Direct Flow Technology (DFT), an inconel 45mm valve, and cast stainless steel base capable of controlling 700+ HP.

Turbonetics is pleased to announce that the new RG-45 Wastegate p/n 11240 is now shipping. Completely designed from the ground up, Turbonetics engineers threw out the rule book when creating this new middle-weight wastegate. Capable of comfortably handling 700+ HP and only measuring slightly more than the super slim Evolution Wastegate, the RG-45 features V-Band connections in and out, 45mm valve diameter and cast stainless steel base for strength and durability.

The brand new RG-45 replaces the legendary Racegate p/n 10307 (now discontinued) in our wastegate lineup. Built with the latest technology such as an inconel valve to withstand high exhaust gas temperatures, high temp fluro-silicone diaphragm for predictable and repeatable boost control, and V-Band connections all in a very small frame size. Like its name suggests the gate has a 1.77''/45mm valve and is good for powerplants making 700+ HP.

The RG-45 is also able to be bolted on to the Tial 44mm gate V-Band flanges with the (21912 optional adaptor flange) to make this a direct replacement with no modifications necessary.

RG-45 Features:

• 45mm Valve - Able to control 700+ HP
• DFT - Directed Flow Technology uses active design to move exhaust gases out of the main body chamber
• Investment Cast Stainless Steel - Corrosion resistance & strength
• V-Band flanges - Inlet and discharge are made for easy installation and adjustments
• Multiple Boost Ports - For clean and simple installation
• 11 psi spring installed - Comes with 5, 8, as well as 15 psi springs
• Turbonetics stand-off base design - Provides cooling for the valve and diaphragm insulation

For three decades, Turbonetics has been a leading source for turbochargers, heat exchangers, controls and related forced induction performance items. Today, Turbonetics manufactures turbo and intercooler products for gasoline as well as diesel passenger and industrial applications. It is Turbonetics mission to produce the highest quality performance forced induction systems, components and accessories, resulting in unsurpassed customer satisfaction and leading edge technology, based on a proven history of engineering and racing experience. All Turbonetics products are backed by a one year, no-fault / no-hassle warranty.

The advent of advanced cellular communications technology has unleashed tremendous potential in remote monitoring systems, which no longer need to be constrained by the limitations of obsolete long-range communication interfaces. This white paper explores how system integrators can close the performance gap between cellular and wired communications even further so that cellular networks can deliver advanced, bandwidth-heavy features such as live video at the central monitoring station.

Industrial computers need to be designed to withstand vibration and shock, which are a fact of life in many industrial applications. This white paper first explains some background about the physics behind vibration and shock, and then explores the specific mechanisms and technology used to build an industrial computer with high resilience against vibration and shock.