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PROFIBUS问题解答22例

菜鸟
2007-09-19 17:01:07     打赏
先给大家提供英文的,以后给大家提供中文的。
  
  1. What Bus type does your system implement. Examples CMSA/BA, CMSA/CD,
  master/slave, multiple masters etc.
  PROFIBUS is based on a Token principle with underlying Master/ Slave communication
  (hybrid media access).
  Services:
  SDN-Send Data with no acknowledge (can be used for multicast/broadcast)
  SDA- Send Data with acknowledge
  SRD- Send and Reply with Data (for efficient bi-directional data transfer)

2. What is the maximum number of nodes that the network can support.
  PROFIBUS allows up to 32 nodes per segment and up to 126 nodes for one network.
   3. What is the Bus topology.
  The base technology is a line which allows connection and removal of nodes at any time without breakdown.
  PROFBUS allows ring and star topology as well with fiber optics.
  
  4. What is the maximum transmission distance without repeaters. What baud rate
  is supported at this maximum distance.
  The maximum distance would be 1000m by using copper with baudrates between
The maximum length may be extended with fiber optic links (up to 2300/15000 m per link)
  
  5. What types of transmission media are used and supported.
  · Copper cable (shielded twisted pair- known as IBM type 1 cable)
  · solid and stranded cable
  · specialized materials for plastic surrounding
  · fiber optic
  · in glass
  · in plastic
  · Infrared
  6. How many bits are allocated at a node for input and output data.
  PROFIBUS allows between 0 and 244 byte, determined by the device requirements for input and output each.
  
  7. How is the bus powered.
  There is no specialized bus power supply. The terminal resistors with pullup and
  pulldown are located at the end of the line and powered be the devices on that place. One combination is enough to run the system.
  
  8. If the bus provides power to field devices what current level is available.
  PROFIBUS PA does supply power for intrinsic safe devices connected with twisted pair.
  This is done according to IEC 1158-2 specification (maximum current is 120 mA per coupler for intrinsic safe operation and >300mA for non intrinsic safe operation).
  9. How are node addresses set.
  Two methods are supported:
  · DIP switches or similar techniques
  · setting of the node address via the bus connection
  Any choice is possible
  
  10. Does the bus provide duplicate address detection.
  Configuration checks for duplicate addresses.
  Masters will look for duplicate addresses before entering the token ring and when unexpected frames are received.
  Slave must be set up with their ident-number and with their configuration. In case of a mismatch, this will be reported to the masters application.
  
  11. Does the bus provide an address attendance check after the first scan.
  · through a so called live list
  · scanning of configured slaves is done cyclic
  · scanning for new masters is executed all time
  
  12. Does the bus provide a node configuration check after the first scan.
  Yes, with the function config_check after power up.
  In addition, the ident number is also checked.
  
  13. Does the bus provide error detection and correction algorithms.
  PROFIBUS has a variety of error detection capabilities
  · Checkbits in every byte
  · Checksum for every message
  · Startdelimiters for efficient frame detection
  · Addressing information (source and destination)
  · Inactivity detection to find out the beginning
  · Transmitter check at the master devices
  · Monitoring the token passing procedures
  · The error correction is done by retries.
  · PROFIBUS includes message duplication capabilities
  
  14. Can a node provide parameter programming. Examples logic inversion and
  similar Boolean operations. Explain any extended detection.
  There are several ways for parameter setup:
  · PROFIBUS allows the individual set of parameters (a maximum of 237 Bytes) during the startup
  · Acyclic exchange of parameters at runtime.
  · Parameter load from a PC by a second master
  
  15. What I/O granularity does the Bus support.
  · The minimum is one byte
  · The granularity is determined by the device
  · Integer, unsigned, floating point, string and structures of the base types are possible.
  · A node may have IO-modules with the granularity of one bit.
  · There are various links available connecting subordinated bit-level busses (i.e. AS-I)
  
  16. What minimum address space allocation does the bus provide.
  This is determined by the device, the minimum would be one byte.
  
  17. What is the cost per point of an AC input/output and a DC input/output.
  Include the most cost efficient implementation as well as the cost to add a single
  bit of I/O as a node to the network.
  DC input and output is about ......$ list price per channel for ET200M cards.
  AC input and output is about ......$ list price per channel for ET200M cards.
  The list price of a small node is approx. .......$ for ET200L but this unit has 16 Inputs onboard
  
  18. What is the protocol efficiency of this Bus.
  The protocol efficiency may be up to 70%.
  The configurations mentioned in the performance metrics section have a efficiency of
  40%. This figures are configuration dependent.
  
  19. Does the Bus support multiple protocols.
  · PROFIBUS FMS,
  · DP
  · DP extensions
  may use the same link and may be implemented in one node
  
  20. How many vendors support this technology.
  Latest number the PTO provided is a membership of 800 with more than 1600 different devices.
  
  21. What form factors are supported for network scanner cards.
  · For Personal computers: PCI, PCMCIA, PC 104 ISA and VME.
  · All known PLCs at moderate size may be equipped with PROFIBUS cards
  (including AB, Modicon, GE, Mitsubishi)
  · Various other solutions are offered
  
  22. What governing body controls this standard. Are changes to the specification
  immediately released to all 3rd party vendors.
  PROFIBUS is controlled through PROFIBUS International and presented through 20
  organizations worldwide. Every add on or change will be defined within the different working groups(18 groups are registered now), every member can participate in the various working groups. All specifications must be released by the Board and are available for all members and non member.
  The working groups are initiated and controlled by the technical committees and the board.



关键词: PROFIBUS     问题解答     22例    

菜鸟
2007-09-19 17:01:49     打赏
2楼
 的确是好资料呀,大家可以安个在线翻译看看呀,这样一来还锻炼自己的英文水平呢,这不是一举两得的好事吗,哈哈!

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