Answer When Citect reads tags from a PLC, it is sometimes quicker to request a block of tags which includes several of those needed by Citect. Sign up for a new account in our community. You need to be a member in order to leave a comment. Posted 18 Dec edited. The OPC specification isn’t exactly clear as to whether it is legal for the OPC Server calls to fail if an access path is not specified, but it does go as far as saying that by “convention” a server should select an access path if one is not provided. It can automatically scan and find devices if you want it to, and that takes a lot of the configuration out of the way.
|Date Added:||21 August 2009|
|File Size:||43.30 Mb|
|Operating Systems:||Windows NT/2000/XP/2003/2003/7/8/10 MacOS 10/X|
|Price:||Free* [*Free Regsitration Required]|
Question The OPC specification uses tag names rather than physical addressing to request the value of a tag. As I said earlier these settings worked for OUR project in version 6. Question I have a customer who tries to connect to an OPC Server and they always get the error.
I ‘m sorry this is a bit vague but I havn’t used version 7 and I clietn that it is very different as far as OPC citecg concerned to previous versions. Posted 18 Dec Citect does not allow the ability to specify access paths for items.
Citect OPC Client Connecting – HMI & SCADA –
I am listing the configurations, hope those who are familiar can verify it for me thanks. We have a large project in citevt 6. Share this post Link to post Share on other sites. Question Do the ‘Response times’ shown in the Citect kernel eg.
This is because Citect has no control over whether the OPC Server optimises requests to the device in the most efficient manner. OPC Explorer is freely downloadable http: Register a new account.
OPC Explorer is not a replacement for Citect, it’s just used for testing.
It’s available as a free 30 day demo here: Sign In Sign Up. With this in mind, Ci Technologies suggest that an OPC Server should handle the case where an access path is not specified.
You need to be a member in order to leave a comment. This will signifcantly load the network and have a corresponding affect on the performance of the Citect system as a whole. Is there any possibility to use the Access path in Citect? Wow, that’s an ambiguous error. You could use it to connect to the OPC Server and verify: That the OPC Server can connect to the end devices. Answer The Access Path is a server specific option that is intended to allow the client to provide a ‘recommendation’ to the server regarding how to get to the data.
Some frequently asked questions are listed below.
By using tag names to access the value of a tag, Citect cannot logically ‘block’ several requests into one request and so the overhead cannot be eliminated. Answer When Citect reads tags from a PLC, it is sometimes quicker to request a block of tags which includes several of those needed by Citect.
Started by jaxrpc18 Dec Sign up for a new account in our community. Then check the Citect.
Citect OPC Client Connecting
Sorry forgot about the problem Sign in Already have an account? It may be that an OPC Server allows items to be specified in a format similar to the native cient format of the device, though this is not necessarily the case.
This is because each request has a specific overhead in time independent of how many tags are being requested, so by making one larger request instead of many smaller requests reduces the average overhead per tag. Posted 19 Dec This means that the response times shown in Citect for the standard drivers eg. The OPC specification isn’t exactly clear as to whether it is legal for the OPC Server calls to fail if an access path is not specified, but it does go as far as saying that by “convention” a server should select an access path if one is not provided.