Genius Webinar series, August 2013 Troubleshooting OPC Genius Webinar series, August 2013

Goals of today’s training Give an overview of OPC architecture Define OPC roles Review some troubleshooting techniques Cover some common problems and solutions You should be positioned to solve 80-90% of OPC errors

What is OPC? Let’s define the acronym Originally meant “OLE for Process Control” In November of 2011, the OPC Foundation officially renamed it to mean “Open Platform Communications”. Let’s define our scope There are many OPC standards OPC Alarms & Events OPC Batch OPC Historical Data Access …and many others We are only talking about OPC Data Access 2.0a today. There are no Rockwell products that use these other standards.

Proprietary Communication Why OPC? In olden times, applications had their own built-in drivers. Example: AdvisorPC, ControlView Disadvantage: when new devices appeared, product had to go through the entire product release cycle. Application Software With Proprietary Communication Drivers

OPC protocol defined by OPC Foundation Why OPC? Eventually vendors found it easier to create “data servers”. Much less effort to make changes to comms. Original standard was Microsoft’s DDE protocol, part of Microsoft Office suite. Over time, data acquisition needs outgrew DDE’s capacity. The OPC Foundation was formed and the OPC standard was introduced. OPC Server OPC protocol defined by OPC Foundation OPC Client #1 OPC Client #2 See www.opcfoundation.org for lists of servers

OPC Architecture OPC consists of: Clients Servers OPC Middleman between clients and control devices Optimizes data requests Talk to servers Examples: SE, FTTM, RSView32, 3rd-party HMI

Good Troubleshooting Techniques Divide and conquer Check connection between OPC server computer and processor. Ping (for Ethernet networks) RSWho Data Monitor (available through right-click on processor) If practical, connect OPC server directly to processor. Check connection between OPC client and OPC Server Get a 2nd opinion: can a different OPC client connect (OPC Test Client, Rockwell Software Data Client)? If client is on a remote computer, try running it on the server.

Good Troubleshooting Techniques Go to the source (the OPC server) Communication servers are in best position to know what the error is. RSLinx diagnostics are your friend. DDE/OPC--> Communication Events. DDE/OPC--> Active Topics/Items. Check the knowledgebase for information on these errors. 30094 - RSLinx Classic: OPC/DDE Communication Event Log Error Messages Others as well.

Common Communication Problems

List of Common Problems Topic not configured properly. Processor not connected / powered up. Wrong program loaded. Too much traffic (network or processor). Firewall blocks connection to the OPC server. RSLinx Classic is not activated. Bad address in packets cause problems for other good addresses.

Topic not configured properly Causes: Topic points to something other than a controller (workstation?) Topic has the wrong device type specified Name is spelled wrong Identification: When clicking on topic, controller is not highlighted Communication event log contains errors like: This is an undefined topic. Verify the topic is in the current project. When loading this topic, it was not possible to resolve the target path that is part of the topic's configuration Best Practice: Let RSLinx create topic using the right-click method!

Processor not connected / powered up. Causes: Controller is turned off. Cable is disconnected. Identification: Walk over to the chassis and look. Ping (if using Ethernet) See if device shows up in RSWho

Wrong program loaded Causes: Someone downloaded the wrong program. Controller may have no program (faulted). Topic points to wrong controller Identification: Go online and verify the program is correct (also Data Monitor). Check to see if processor has any faults or LEDs. Double-check address and type of processor.

Too much traffic (network or processor). Causes: Controller is busy (ladder, MSG, periodic tasks, etc). Network is busy (too many requests and too fast). Identification Putting controller in Program mode solves problem (bottleneck is the controller). Limiting Maximum Packets in topic fixes the problem (bottleneck is network or controller). Check communication log for “application layer timed out…”

Firewall blocks connection Causes: Someone undoes the changes made to Windows Firewall. (More likely) A 3rd-party firewall has been installed or hardware firewall is blocking ports. Identification: OPC Test Client fails when selecting the server. RSLinx Classic DDE/OPC--> Active Topics/Items shows no topics are active. See 29402 - TCP/UDP Ports Used by Rockwell Automation Products for a list of relevant ports.

RSLinx Classic is not activated Causes: No activation was purchased. Wrong activation (remote clients required Gateway license). Activation was corrupt. Note – no activation is required for FactoryTalk View SE or ME to connect to RSLinx Classic. However other OPC or DDE clients still required this activation. So RSView32 would not be able to communicate to RSLinx Lite. Identification: RSLinx title bar shows “RSLinx Lite” Clients try to connect to “Remote RSLinx OPC Server” but no RSLinx Gateway activation is present.

Bad addresses in packet Cause: At least 1 non-existent addresses is in the same packet as other good addresses Identification: Common behavior: Clients seem to work initially but stop working as more screens are opened. RSLinx communication event log contains “tag or item does not exist”. OPC Test Client can see the data but other clients cannot (this could also be caused by other things).

Summary Always use “Divide and conquer” to narrow the scope of the problem. Take advantage of communication event log and other diagnostics. Be sure to check the knowledgebase for details on specific errors. Get a 2nd opinion using the OPC Test Client Questions?