Transcript Document
HMI/SCADA to RTU Connectivity for Water & Utilities via DNP 3.0 Using the TOP Server DNP Driver Presenter: Boyce Baine, Sr. Applications Engineer Agenda Introduction DNP Drivers Overview What is TOP Server Overview of DNP and how it differs from normal “polling” PLC drivers & protocols Overview of Driver settings & configuration Testing your configuration Q & A & other Resources What is TOP Server? TOP Server Gets You Connected! http://www.toolboxopc.com/html/drivers_list.asp What is DNP and Who Uses It? DNP3 (Distributed Network Protocol) is a set of communications protocols used between components in process automation systems It is primarily used for communications between a master station and RTUs or IEDs. Originally designed for power distribution and transmission, DNP has found a home in water/wastewater, oil/gas and transportation. TOP Server DNP Master Driver Suite Overview Plugs in like any other TOP Server Driver Licensed as an individual suite based on number of RTUs (10, 50, unlimited) Will be included in the Power Distribution Suite (Coming in 2010) Serial RS-232/422/485 or Ethernet connections Supports DNP 3.0 Level 3 compliant slave devices Ethernet Encapsulation supported which allows use of Cellular Radios & other encapsulation devices Supports standard TOP Server protocol diagnostics Serial driver supports Dial-Up Modems Key Differences from other TOP Server Drivers Key differences DNP is a Synchronous Protocol Unsolicited Messages & report by exception really helps efficiency with remote devices. In proper DNP3 usage Demand Polling option Allows for operation like a regular polling driver – however, you give up the benefits of the DNP protocol in terms of bandwidth utilization and report by exception. Ethernet Encapsulation done at Channel level, not device level Restart requirements Dependency on proper slave device configuration is greater Important to Understand Decoupled scan rates & separate scan loops for client/server and DNP master/slave No relation between client items configured and what gets scanned by the driver layer Timeout Settings DNP Polling Settings Your slave device configuration Naming syntax of items and correlation with DNP slave documentation Differences DNP is a Synchronous Protocol Only one thing at a time can happen Each command requires an acknowledgement, confirmed failure, or timeout before the master can move on to the next command So things may never be as fast as other protocols! Most serial protocols are this way- but DNP more so The DNP stack queues up messages to be sent, so a command can spend time waiting in a queue inside the DNP stack- this is in addition to any internal TOP Server queues Asking for too much too fast can be painful However, due to the report by exception nature of DNP when properly used, it is very efficient for bandwidth utilization – only changes are sent Proper use is: Avoiding demand polling Reasonable Integrity and Event Poll intervals for the amount of data your device sends and your connection speed Important Learning Topic: Decoupling of Scan Rates – How Normal PLC drivers work How things work with most drivers Topic/Group scan rate drives the device polling rate Topic or Group Update Rate : 100 ms HMI or Client App. Driver to PLC Scan Rate: 100 ms Tag PLCAddr Tag1 40001 Tag2 40002 Tag3 40003 Tag4 40004 Tag5 40005 Tag6 40006 Tag7 40007 Tag8 40008 Tag9 40009 Driver Scan of PLC Important Learning Topic: Decoupling of Scan Rates – How it works in DNP if used properly Scan Rates are Independent – Completely! If you use Demand Polling in DNP, then you end up making it work like a regular driver (see prior slide) and give up the report by exception efficiency of DNP! Topic or Group Update Rate: 100 ms Topic Group Update rate determines how fast data buffer is checked for changes No linkage! Client Interface Layer Driver Layer Data Buffer Tag PLCAddr PLCAddr Tag1 40001 40001 Tag2 40002 40002 Tag3 40003 40003 Tag4 40004 40004 Tag5 40005 40005 Tag6 40006 40006 Tag7 40007 40007 Tag8 40008 40008 Tag9 40009 40009 Driver to DNP Slave Scan Rates determined by Driver configuration Driver does integrity and event polls of the DNP Slave or receives unsolicited messages and updates data buffer Differences To insure full restart of driver stack, restart the server Title says it all Nature of the beast with the separate polling cycles between driver and OPC side which is very different from the closer coupling that exists with other drivers There can be outgoing messages queued that have not been sent, which means if you only reinitialize the client, the DNP stack will not be reinitialized. A MUST to keep in mind item if you are troubleshooting an issue! TOP Server – User Interface Review, Configuring the DNP Driver So let’s see how to configure the driver – we’ll highlight other key differences as we get to them in configuration Configuration – Add a Channel Configuration – Channel Setup Ethernet Driver In systems with more than one network card and subnet, you can pick which card & subnet to bind to using this combo box Write Optimization settings and why you might change them are covered in detail in the product help file – best to leave at default in most cases Configuration – Channel Setup Ethernet Example Master Node Address must be configured at the slave as well and these must match. Must be unique for each channel. IP Address, Slave Port and Connection type are also configurable at the slave and must match these settings. If DNP Connection is set to UDP, you also must configure the UDP Listener port at the slave and master. Configuration – Channel Setup Serial Example Pick your com port – any standard Windows com port will work. COM1 through COM100 supported Set remaining serial port settings to match your device If your PC has a modem installed (internal or external) this checkbox will be available For use with serial/ethernet converters, terminal server devices, and also with some cellular radios Configuration – Channel Setup Serial Example w/Modems This checkbox can only be enabled if you have a Windows TAPI compliant Modem installed in the computer. If enabled you can check it to use your modem You can choose which modem you want to use here See product help file for full details on how to configure phonebook entries, special dial,hangup tags, etc Configuration – Channel Setup Serial Ethernet Encapsulated Example In systems with more than one network card and subnet, you can pick which card & subnet to bind to If the Ethernet using this combo Connection on your DNP box Slave device is provided by a serial/ethernet encapsulation IP Address, device/terminal server Port and type must match and theProtocol actual end the settings device is a DNP serial in the encapsulation device you’ll check this device. box The amount of time allowed for a TCP socket connection to initially be established to the device. Non-relevant/ignored when using UDP connections. Configuration - Channel Important Considerations DNP Master ID is at the channel level and must be unique for each Channel If you want unsolicited messaging to work, you have to get this right so the Slaves know where the master is! Encapsulation or Ethernet parameters are set at the channel level If you have > 1 serial slave device but are using Ethernet/Serial convertors, each with it’s own Encapsulation device or if the slave is Ethernet capable, each device will be under it’s OWN channel Probably a good thing for performance since each channel is a unique thread Configuration – Channel Setup Understanding Timeout Settings DNP Channel Timeout (Channel Properties) DNP Connection Timeout – used with TCP only – non-relevant with UDP Channel Level Controls timeout for the time on the wire between Master & Slave only – no queue time Time to get the TCP connection up and going DNP Command Timeout (Device Properties) Device Level Time On Wire + Time In Queue Should generally be > DNP Channel Timeout! Understanding Timeout Settings Talking to multiple devices will take time if you have multiple slaves off of one channel In Ethernet or Encapsulated Cellular radio scenarios, a non-issue since it’s 1 device per channel Rule for timeouts if multiple devices under one channel: DNP Command Timeout = (# Devices under Channel +1 ) * DNP Channel Timeout Example: DNP Channel timeout = 10 seconds ( default ) 1 Device, 1 Channel DNP Command timeout = (1+1) * 10 = 20 seconds Configuration – Channel Summary Configuration – Device Settings You’ll see this under the channel you just configured – click it to start the Device Configuration Wizard Give your device a name that is useful to you. This is the DNP Slave ID of your device – it is required for Ethernet or Serial Device. This MUST match your slave device! DNP Polling Types Integrity Event Supplies changes since last Event or Integrity Poll, including buffered events if configured on slave Make sure your slave is configured to send timestamps! Many are by default, but if you aren’t getting the timestamps you expect….check the slave device settings Unsolicited Gets All the data from the device – usually done at startup and infrequently Slave sends changes to Master based on policy configured in slave What is sent and when, plus retry policy & timing is set on the slave If you depend on unsolicited messages, beware of your firewall! Unsolicited TCP/IP and UDP packets will be rejected unless you’ve planned for them Demand (configured at the tag/item level) Traditional master polling of slave – gets data whether changed or not. Bypasses DNP efficiencies. Not recommended unless you have to! Polling rate driven by Topic or Group Update Rate DNP Polling Typical Use Cases With DNP you can connect and initialize the session and: Or…Most Commonly…. after the initial Integrity Poll Do an Integrity Poll, Then sit and listen for unsolicited messages and never do an Event Poll You can do an Event Poll at some interval to get just items changed since last report from the slave & change history if enabled at slave and master You can do an Integrity Poll at a regular interval to ask for an update of ALL items And receive unsolicited messages, if configured in slave Sometimes devices have data that can only be read by doing explicit reads (“Demand Polling”) Configuration – Device Settings Polling Settings Controls how often driver will ask DNP Slave for a report of all • Controls ask DNP slave for values of changes sincehow last often Eventdriver Poll orwill last Unsolicited Message. Three ALL the slave, regardless ofwith whether youevent havepoll classes ininDNP can configured different DNP Command Timeoutevent should beitems greater than thebechannel timeout OPC setup for them, regardless of whether values rates.covers Seeitems your slave documentation for what points The DNP Command timeout time DNP on the wire (Channel timeout) and time in are in each have class changes – it may be configurable. the queue • 0 = do no Integrity polls, ever – not recommended Value = 2,592,000 seconds (30 days) 0 =• doMax no Event Polls, ever, rely on period integrity polls, Formula: • We recommend more than once per especially in unsolicited messages no or explicit reads only forhour, updates. radio or wireless networks. Most applications even less value 86,400 seconds (24 hours) DNP Command TimeoutMax should be = >= frequent, every 8 hours or 24 hours isSetting sufficient. The max is (# of DNP Devices Under a Channel + 1) * DNP Channel Timeout 30 days. (set on your channel properties) Configuration – Device Settings Advanced Settings Two Options: LAN Two Options: Serial Direct Operate Twothen Options: Select Operate UTC Determines Localafter Timewrite action from to If the Master slave can reportSlave an I/O point as offline, this allows the server to set the quality to bad for the .Value and .Explicit subtypes Configuration – Device Settings Unsolicited Messaging Setup and Considerations Unsolicited messages update master with changes If the slave If the slave accepts unsolicited No Action accepts in the device accepts unsolicited setting commandsthe settings from setting commands from the master,deadbands the slave. If the Slave device controls settings on item from the master, this tells the slave slave does not and Unsolicited messages (number and frequency), this tells the slave to disable accept unsolicited to enable unsolicited messaging NOT THE MASTER! unsolicited messaging. commands from messaging. the master, Deadband settings in a slave can prevent you the from other two settings receiving EVERY change – a good or bad are thing irrelevant. based on your needs Our Master CAN control which classes of Unsolicited Messages get sent, IF the SLAVE will accept our command messages… they aren’t required to! But the Master can’t control unsolicited message settings at the slave any more granurally than this Configuration – Device Settings DNP Event Buffering: Overview What happens when communications are lost? Most non DNP devices/protocols miss out on that data. DNP slaves can buffer data and then send the events when communications are established. Whether or not your slave buffers, how much it buffers, how it handles a buffer overrun, are all your slave hardware’s settings outside the scope of the TOP Server and it’s support. When communications comes back A properly configured DNP system will have the slave replay the old events with the timestamps of when the event happened! TOP Server can Buffer up to a specified # of events Play them back at a user configurable rate that your client/Historian can handle for logging The events play back in the same order we receive them from the slave – provided the slave delivers them in FIFO timestamp order, then our delivery to HMI/SCADA will be the same. Configuration – Device Settings DNP Event Buffering: Supported Objects Event Buffering applies to DNP objects 1 – Binary Input 3 – Double Bit Input 10 – Binary Output 20 – Binary Counter 21 – Frozen Counter 30 – Analog Input See driver help file for more details Configuration – Device Settings DNP Event Buffering: Important Considerations Event Buffering introduces latency into the tags for those affected objects. Even after the initial burst of events is played out of the buffer, newly incoming updates will only be reported at the Playback Rate. Buffering should only be used when preservation of the event stream is more important than timely delivery of point updates. Event Buffering is enabled at the device level If a tag's event buffer should fill up, new reports will displace the oldest reports in the queue. Configuration – Device Settings DNP Event Buffering: Configuration There are three settings to configure when you use event buffering. In this example To insure the buffer retrieval ofwill all retain 100 the buffered updates events,per thetag and make the client must next update have an update available to the rate at least client twice as once fast as every 2000 the Playback milliseconds. Rate (less than 1000 milliseconds in this example). First, we must enable event buffering. Configure the max events per tag, 11000. Configure the playback rate. Configuration – Device Settings Click “Finish” and you’re Done! Configuration Setting up DNP Tags/Items Must have DNP slave profile document Slave profile is not some file you load into the driver! But it is a key document that a DNP3 compliant slave device must provide! User must read over it and be responsible for interfacing with their h/w vendor on questions about their document Understand the basics of the DNP standard item naming syntax Configuration Addressing DNP Items Address follows OBJ.VAR.IDX.SUB syntax: OBJ=Data object group (i.e. analog inputs, analog outputs, etc) VAR=Variation (equates to data type) IDX=Data object within a group (OBJ) – i.e. IDX 4 would be the 5th point in a group SUB=Specific attribute of a point Most commonly used is “Value” Use “Explicit” to cause the tag to be “Demand Polled” – makes that tag work just like traditional polling PLC driver – use with care! Configuration Setting up DNP Tags/Items: Example Example – Multitrode Multismart Chapter 3 gives you list of Object #s (OBJ) Chapter 4 gives you the IDX but they call it “Default DNP ID” Depending on the quality of your DNP slave documentation, this might take some trial & error or you may have to ask the hardware supplier for clarification Configuration DNP Addressing Examples Analog Input 30.0.51.Value 30 = Analog inputs object 0 = Variation = default data type 3 = index, sometimes called Default DNP ID Value = report the value of the input Binary Input 1.0.2.Timestamp 1 = Binary inputs object 0 = Variation = default data type 42 = index, sometimes called Default DNP ID Timestamp = report the time of the event currently reported by the .Value sub-attribute Configuration: DNP Addressing Important Subtleties to Know In proper DNP implementation, the # of tags or OPC items you configure in the OPC server has no effect on what gets scanned or updated from the DNP slave – that’s how DNP works! The driver abstracts a lot of DNP Slave profile details for you – so try not to get bogged down in the details. Focus on finding the OBJ.VAR.IDX.SUB lists for the tags you want in the DNP Slave profile If you don’t see an object # from your slave profile listed in the driver help file, does not mean it’s not supported – some object #s are implied when you use the base object. Example: Change Event objects are used “under the hood” automatically Same with writing objects See “Address Descriptions->Object Definitions” in help file – a list of objects whose data is reflected in other objects is provided there! Object 30 – Analog Inputs – using object 30 will also cause object 32 to be used “under the hood” for analog input change events. When in doubt, try the base object # for the Object Group (i.e analog ins, analog outs, etc) for the OBJ part of the address and try the things you want to do Testing Communications OPC Quick Client If launched from the Server, it will auto-populate all tags Tag configured in the Server detail view Server connection and OPC Group tree OPC Quick Client Event Log Tips & Tricks Loads of free help at: http://www.toolboxopc.com/html/support.asp Quick Start Guide Training Videos Papers and Utilities – Trouble Shooting Guide More information on the Product Details tab http://www.toolboxopc.com/html/product_details.html Contact Software Toolbox [email protected] while you are in the planning stage, so we can help Contact Information & Other Learning Opportunities Questions later? Boyce Baine [email protected] www.toolboxopc.com www.softwaretoolbox.com Other learning opportunities Visit www.softwaretoolbox.com/webinars [email protected] 888-665-3678 or 704-849-2773