FLEX热备方案.docx

1、FLEX热备方案FlexLogix Backup on DeviceNetApplication NoteFlexLogix的DeviceNet网络备份应用说明March 200320003031. FlexLogix backup on devicenet Overview综述 31.1 Typical Applications典型应用 31.1.1 Power Generation发电 31.1.2 Remote RTU for SCADA远程终端的管理控制的数据采集 31.1.3 Small Process小过程 31.2 DeviceNet Technology Used驱动技术应用

2、31.3 System REquirements系统需求 31.4 Architectural Overview结构总貌 51.4.1 How FlexLogix Backup works如何工作 52. developing the FlexLogix Backup application备份应用的发展 62.1 accessing Backup configuration from the user program从用户程序访问备份结构 62.2 Backup Heartbeat configuration备份心跳结构 62.3 Reading backup state读备份规定 62.4

3、 reading backup status读备份状况 62.5 Example get Attribute Single MSG instruction获得单MSG指令属性的例子 72.6 Example Set Attribute Single MSG Instruction设置单MSG指令属性的例子 92.7 Example Ladder to enable backup mode梯形图使能备份模式的例子 112.8 Configuring the Scan lists in primary and secondary在第一和第二处理器配置扫描列表 152.9 Tips for deve

4、lopment and debugging发展和调试 153. powerup and system startup上电和系统启动 163.1 Example step to qualify a backup system逐步限制备份系统的例子 163.2 using leds for status利用二极管的状态 174. FAQ常见问题 185. ControlLogix and flexLogix comparison比较 201. FlexLogix backup on devicenet Overview综述FlexLogix Backup on DeviceNet is a sim

5、ple, low-cost, backup system targeted towards smaller applications which require fast switchovers from Primary to Secondary processor. No additional HW or special SW is required. FlexLogix Backup is faster than a SW implemented switchover (i.e. inhibit/uninhibit) and lower cost than ControlLogix Red

6、undancy on ControlNet.FlexLogix的DeviceNet网络的备份是一种简单、低成本。备份系统针对的是要求快速从第一处理器切换到第二处理器的小的应用场合。不需要额外的HW或专门的SW设备。FlexLogix备份切换速度比SW快、比ControlLogix 的ControlNet冗余网低成本。1.1 Typical Applications典型应用In general Backup capability will fulfill two general requirements:一般而言完成工作需要2个普通要求:- Minimize Down Time in case

7、of Processor failure (same program in both processors).- 处理器故障的最小停机时间（相同的程序在2个处理器里）- Mitigate Risk of changes adversely affecting the application (use old, proven program in one processor and new, untested program in other processor). In case the new untested program causes a problem, a forced switc

8、hover can be made to the older proven program without re-downloading the program.- 减小应用程序改变的相对影响（在一个处理器中用旧的证明过的程序，另一个中使用未测试过的程序）。万一新的程序引起故障，强制切换能切换到旧的程序。1.1.1 Power Generation发电FlexLogix Backup is ideal for power generation applications which require a low-cost backup processor to minimize down time

9、. A typical application would involve using a redundant pair of processors to control the switch gears, or for standby or power cogeneration.1.1.2 Remote RTU for SCADA远程终端的管理控制的数据采集Since many RTU (Remote Terminal Unit) applications for SCADA (Supervisory Control And Data Acquisition) are located in

10、remote locations, backup processors are required since the mean time to repair may be quite long.1.1.3 Small Process小过程In small process applications where environmental control is critical (e.g. loss of temperature causes whole batch to be thrown away), a backup processor is required to avoid loss o

11、f the whole batch in case of processor failure (e.g. power failure).1.2 DeviceNet Technology Used驱动技术应用The Allen-Bradley technology behind the backup functionality is the ability to have Shared DeviceNet Mastership of slave I/O devices. Typically with DeviceNet only a single master may exist on the

12、network for any particular slave. With Shared DeviceNet Mastership, a simple backup system can be implemented. The heartbeat communications between Primary and Secondary determines which scanner is the master and which scanner is in standby. The technology is not unique to FlexLogix but currently th

13、e 1788-DNBO is the only DeviceNet scanner which supports this feature.1.3 System REquirements系统需求RSLogix5000 and FlexLogix FW revision must be v10 or higher at a minimum.- FlexLogix FW must be at v10 or higher for 1788-DNBO support- FlexLogix FW must be at v11 or higher for 1788-ENBT support- 1788-D

14、NBO FW must be at 2.X or higherThe DeviceNet network should be setup with both the primary and secondary 1788-DNBO node addresses set to 0. Node 1 should be reserved for the secondary scanner. (It is also possible to use higher node numbers such as 10 and 11, or 30 and 31, but not 62 and 63.)All I/O

15、 and operator interfaces that are required to be backed up must be on DeviceNet. 1.4 Architectural Overview结构总貌1.4.1 How FlexLogix Backup works如何工作Refer to the previous picture.以上图片提到的- Both processors/scanners simultaneously receive all inputs- 2个控制器/扫描器同时接受所有输入- Both processors execute in parallel

16、 but are NOT synchronized.- 2个控制器并行执行但是不同步- Only Primary sends Outputs to I/O devices. (A virtual switch in the 1788-DNBOs is used to switch outputs between Primary and Secondary.)- 只有主控制器送输出到I/O驱动（在1788-DNBOs有一个虚假的切换用于在主、从控制器切换输出）。- After failure or forced switchover, Outputs are automatically swit

17、ched by 1788-DNBO from Primary to Secondary- 故障或强制切换时，输出会自动通过1788-DNBO进行主、从切换。The switchover so fast that the I/O does not time out. The I/O is unaware that redundant processors/scanners exist and is unaware of the switchover.切换给I/O是非常快的，不需要时间。冗余的控制器和扫描器切换，I/O是不会觉察的。2. developing the FlexLogix Backu

18、p application备份应用的发展2.1 accessing Backup configuration from the user program从用户程序访问备份结构Backup mode is enabled from the User Program with a few simple ladder rungs (or equivalent). The first and most critical step is to set the backup “heartbeat” constant inside the DeviceNet scanner, which determine

19、s the switchover time (2 x heartbeat) and enables the backup feature. By default the heartbeat is initialized to zero, which disables the backup mode so the User Program must set the heartbeat to a non-zero value to enable backup mode.2.2 Backup Heartbeat configuration备份心跳结构The heartbeat is in multi

20、ples of 8ms (i.e. 8, 16, 24, etc.) with a recommended value of 16-48ms for most applications. This results in a switchover of 32-96ms (but doesnt include processor scan delays). If multiples of 8 are not used for the requested heartbeat, then the scanner will use the next higher supported heartbeat

21、value, which can be read from the scanner.心跳是8ms的倍数（如：8，16，24等），最多的应用推荐值是16到48ms。是切换时间为32-96ms（但是不包括扫描器延迟）。假如8ms的倍数不是用来要求心跳，扫描器会用更大的、能从扫描器读数据的支持心跳值。The heartbeat setting within the DeviceNet scanner is accessed by using the Generic Message Instruction and the Set/Get Attribute Single service to Scan

22、ner Class 0x90 + Instance 0x01 + Attribute 0x12 with an INT data type. When the scanner detects a change in the heartbeat, it will reset itself and use the new configuration.2.3 Reading backup state读备份规定The backup state of the scanner can be obtained (e.g. primary or secondary) using the Get Attribu

23、te Single service to Scanner Class 0x90 + Instance 0x01 + Attribute 0x13 with a SINT data type.扫描器备份规定能获得（第一或第二）使用获得单一的扫描服务特征类：0 = Disabled不能1 = Primary Scanner主扫描器2 = Backup Scanner备用扫描器3 = Invalid Primary Node Address (e.g. cant be 62 or 63)故障主节点地址4 = Faulted Backup Scanner - CRC Failure - (e.g. S

24、can Lists dont match) 故障备用扫描器（校验故障）5 = Faulted Backup Scanner - Backup Node Number Failure (e.g. Backup not Primary + 1) 故障备用扫描器，备份节点数值故障6 = Backup Scanner Pending Primary Detection备用扫描器未发现主扫描器254 = Attempting Primary Access尝试主访问255 = Attempting Backup Access尝试备用访问The backup state is useful for debu

25、g or more sophisticated backup schemes.2.4 reading backup status读备份状况Additional status bits are also available using the Get Attribute Single service to Scanner Class 0x90 + Instance 0x01 + Attribute 0x14 with a SINT data type.附加的状况位也可用来获得扫描服务唯一属性。Bit 0 = No Backup Scanner Detected没有备用扫描器Bit 1 = Pri

26、mary Scanner forcing IDLE (Backup in RUN but Primary in IDLE)主扫描器强制空闲2.5 Example get Attribute Single MSG instruction获得单MSG指令属性的例子Screen shots of a example Get Attribute Single MSG instruction. Current_Heartbeat is an INT.2.6 Example Set Attribute Single MSG Instruction设置单MSG指令属性的例子Screen shots of a

27、 example Set Attribute Single MSG instruction. Config_Heartbeat is a INT.2.7 Example Ladder to enable backup mode梯形图使能备份模式的例子An example ladder program using the Get and Set Attributes services to enable Backup Scanner is shown below.2.8 Configuring the Scan lists in primary and secondary在第一和第二处理器配置扫

28、描列表The key to easily configuring the redundant DeviceNet scanners is to configure them separately with only a single scanner on the network at a time. In order for backup to work, both scan lists must be identical.2.9 Tips for development and debugging发展和调试In general it is also a good idea to develo

29、p and debug the entire application with only the primary processor and scanner present. When the application is totally verified, then download the program and exact same scan list to the secondary, without the primary being present. Verify that the secondary is also functioning properly, and then b

30、oth primary and secondary can be added to the network at the same time.NOTE: No configuration parameters are entered from RSNetworx for DeviceNet or RSLogix5000 to enable Backup. All configuration occurs in the User Program. Almost your entire application (e.g. except for a few ladder rungs) can be

31、developed without knowledge that the application will have a backup processor and scanner.3. powerup and system startup上电和系统启动 3.1 Example step to qualify a backup system逐步限制备份系统的例子The following example steps describe the sequence of events taken to configure a FlexLogix Backup system.1) Put all bac

32、ked up I/O and operator interfaces on DeviceNet using node addresses 2 and higher.2) Connect a FlexLogix processor with a 1788-DNBO scanner on the network. Set the node address to 0. Powerup the controller and network.3) Using RSNetWorx for DeviceNet, download a scan list to the 1788-DNBO to allow communication to slave devices on network. This could be a freshly made configuration or a previously created project. If a fresh configuration, make su