ngoodman Posted January 6, 2011 Share Posted January 6, 2011 HI simple question remote connection between 2 copies of daqfactory I have a scada system connecting extruder machines , various services alarms and now a weighing and measuring system . there are 2 remote connections one for a remote viewing screen in the production office and the 2nd is to pull data from a weighing and measuring system. (no more than 30 channels) odd thing happened over the xmas holidays when the weighing machine was switched off we had lots of connection errors to the OPC server running on the server PC? when the weighing machine was back on line all now OK, I have never trusted the OPC server as reliable but this is strange. the OPC server opens port 20000 but has no connections on this port. could it be when the remote connection to the weigher is off line the server and daqfactory try repeat after repeat to reconnect and this causes the OPC to lose sync?? IF so can the remote connection be switched off when not needed and back on when needed ? I ran a port scan the remote connection does not seem to use port 20000 none of the modbus tcp connections are affected by this . not a huge issue but any ideas? Link to comment Share on other sites More sharing options...
AzeoTech Posted January 6, 2011 Share Posted January 6, 2011 The remote DAQFactory uses port 2345 through 2348. There really should not be any interference between it and an OPC server. Does the OPC completely stop working, or just becomes intermittant? Are you sure it corresponds with the remote connection? Link to comment Share on other sites More sharing options...
ngoodman Posted January 7, 2011 Author Share Posted January 7, 2011 The connection between daqfactory and the opc server is lost - I suspect it is the OPC server at fault and yes when the remote connection is established all will work again ?? could daq factory be retrying to connect and this is interupting the connection? if so being able to switch the remote connection on and off will be a reasonable work around. I am trying to move away from the B&R OPC for other reasons so a short / medium term solution would suffice. any ideas? Link to comment Share on other sites More sharing options...
AzeoTech Posted January 7, 2011 Share Posted January 7, 2011 If I have your arrangement right, the system connecting to the OPC server is also the server for the remote DAQFactory systems. When those remotes disconnect, the OPC connection is lost. Am I correct? Unfortunately, the server just acts as a server and so can't tell a remote that's already disconnected to disconnect. The server doesn't try to reconnect, the client (remote) does. Does the OPC server actually come back online when the remote DAQFactory reconnects? You might try turning Windows firewall off... Link to comment Share on other sites More sharing options...
ngoodman Posted January 10, 2011 Author Share Posted January 10, 2011 OK - this may be the answer the server is in effect the client for the weigh station as it reads back the channels . so are you saying that if the weigh station is offline the server (client) will be trying to reconnect to the weigh station.? if so then that may explain why the OPC goes flakey! It looks like its (again ) an OPC software problem , I think the issue is the fact the OPC connects to the machine via virtual serial ports over ethernet so we do have another bit of software running in the backgrouind. so hidden from view is a lot of data transferring when the OPC is reading the OPC refresh is 5 seconds so there should be enough slack time for DAQfactory can the reconnect be suspended until the weighstation is ready? or should the weighstation be doing the connecting? would the server be able to see all the weighstation channels in this way? when everything is running its all pretty rock solid the only issues occur when the weighstation is offline or on start up. Link to comment Share on other sites More sharing options...
AzeoTech Posted January 10, 2011 Share Posted January 10, 2011 Which system has an extra Connection on it? The weigh station or the one running the OPC server? The one with the extra Connection (in addition to Local) is the Client and it is the one doing the connecting. The one that that extra Connection is pointing to is the server and it has no control over the connecting. As for the virtual serial port software: I hate them. They are notoriously unreliable, depending on the provider, and having an extra piece of software just provides another failure point. That's why DAQFactory allows you to put any protocol on any transport layer: you can simply open an Ethernet connection directly to the serial/ethernet converter and skip the virtual comm port. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.