Citect - Multiple IO Servers on a network address

I am trying to solve a Citect problem

I want to combine a couple of IO Servers onto a single computer, however when i put both IO servers onto a single Network Address, I get the following compile error.

A server with this network address and port already exists
COMPUTER:2082



Does this mean that if i want to do this then i need to change the IO Server port to something other than 2082? Has anyone done this before?

Usually the whole point of having two I/O servers is that they can live on different machines and hence offer some redundancy if one of the machine breaks down. Could you please throw some light on why would you want to have two I/O servers on the same computer?.... And yes you should try to change the port, because each I/O server has to have a unique set of network address/port number combination....

Regards.

thanks for the reply moeen.

I have an extra computer running citect that doesn't really need to be there as it was only installed to provide an extra serial port that couldn't be fit into the original computer.

I have since ported the device needing the serial port to ethernet and have written my own cicode to interrogate it. This means that I no longer need the extra computer, i can integrate it into the original computer.

It does not need redundancy as i am not running a citect driver to get this information. Since it is cicode based (and using a DskIO Io device for storage), it needs the computer to be operational anyway (although i could probably run it as a report if i wanted to get redundancy)

Hope that makes sense.

I am going to try deploying it tommorrow (with the non standard ports), and see how it goes.

From what you are saying I gather that you no longer need the other computer's "server" capabilites. If that is the case then why move the server to another citect pc, why not just do without the machine altogether ? If I understood correctly why not just setup your "new" ethernet port on the IOserver that you still use and run it that way ?

Dua Anjing said:

From what you are saying I gather that you no longer need the other computer's "server" capabilites. If that is the case then why move the server to another citect pc, why not just do without the machine altogether ? If I understood correctly why not just setup your "new" ethernet port on the IOserver that you still use and run it that way ?

Click to expand...

Because there are other related things such as disk IO devices and tags etc that i would need to change to the other IO Server as well. I was looking for the quickest, easiest way to merge them!

If this doesn't work, then what you say is my backup.

zankorel said:

Because there are other related things such as disk IO devices and tags etc that i would need to change to the other IO Server as well. I was looking for the quickest, easiest way to merge them!

If this doesn't work, then what you say is my backup.

Click to expand...

Just some feedback, i combined the two IO Servers onto the one Computer this morning and all is working well.

I needed to change both the port and the peer port to non standard numbers.

thanks for the feedback

Hey Guys,

I came across this discussion while searching on how to implement multiple IO servers on the same machine.

My problem is that i have large number of IO devices and i was surprised by the fact that i can only have 255 IO devices per server.

i found in the knowledge base that i can use multiple IO server instances on the same machine using clustring (Knowledge base Q4955 on citect 7.2)

but i do not understand how this goes, i thought of using different port number, but the point is i am using MODNET driver, which sticks me to port 502.

Any help with this?

I must admit that I haven't had a lot of experience with Citect but may be able to help you out. You are correct, you can implement 2 I/O servers on a single machine if using clusters. I recall that the was some Citect documentation that stated that you cannot have multiple server processes of the same type (i.e. 2 different alarm servers, 2 different I/O servers etc) running on the same PC if clustering is NOT used. So this is why the original poster would have being having difficulties. However, using clustering to solve this problem is probably not ideal. For me, clustering is a mechanism that can be primarily used for implementing process area (as in plant process) segmentation within a single Citect project (as opposed to using multiple Citect projects, i.e. one project for every process area). With clustering you can then ensure that alarms (for example) for one particular process area are not annunciated on the Citect clients associated with a different process area (and as such attached to a different cluster). There are probably other uses for clustering but this is one example. An alternative option to using clustering to solve this problem is to use an OPC server (I prefer OPC servers since the drivers are written by the actual PLC vendor) then all you need to do is setup multiple I/O Devices within the Citect project , with each corresponding to a particular OPC Server program (e.g. one I/O Device for RSLinx another for Schneider OFS etc). In this case you would still only have one I/O Server defined in the Citect project but multiple I/O devices. Hussein in your case where you are concerend that you may exceed your I/O device limit, switching to an OPC server would solve your issue. The reason being is that as far as Citect is concerned you will only have 1 I/O Device (this would be your single OPC Server) and only one I/O Server. Then all you would have to do is configure your OPC server to look at your multiple I/O devices (i.e. your PLCs etc)

Alternatively, you could use virtualisation i.e. two Windows sessions running on a single piece of hardware each with their own IP address. Hope this info helps

I must admit that I haven't had a lot of experience with Citect but may be able to help you out. You are correct, you can implement 2 I/O servers on a single machine if using clusters. I recall that the was some Citect documentation that stated that you cannot have multiple server processes of the same type (i.e. 2 different alarm servers, 2 different I/O servers etc) running on the same PC if clustering is NOT used. So this is why the original poster would have being having difficulties. However, using clustering to solve this problem is probably not ideal. For me, clustering is a mechanism that can be primarily used for implementing process area (as in plant process) segmentation within a single Citect project (as opposed to using multiple Citect projects, i.e. one project for every process area). With clustering you can then ensure that alarms (for example) for one particular process area are not annunciated on the Citect clients associated with a different process area (and as such attached to a different cluster). There are probably other uses for clustering but this is one example. An alternative option to using clustering to solve this problem is to use an OPC server (I prefer OPC servers since the drivers are written by the actual PLC vendor) then all you need to do is setup multiple I/O Devices within the Citect project , with each corresponding to a particular OPC Server program (e.g. one I/O Device for RSLinx another for Schneider OFS etc). In this case you would still only have one I/O Server defined in the Citect project but multiple I/O devices. Hussein in your case where you are concerend that you may exceed your I/O device limit, switching to an OPC server would solve your issue. The reason being is that as far as Citect is concerned you will only have 1 I/O Device (this would be your single OPC Server) and only one I/O Server. Then all you would have to do is configure your OPC server to look at your multiple I/O devices (i.e. your PLCs etc)

Alternatively, you could use virtualisation i.e. two Windows sessions running on a single piece of hardware each with their own IP address. Hope this info helps

Citect - Two computers sharing 1 I/O server

Currently run two PCs with redundant I/O servers. The issue I have been having is when starting up the secondary machine it will fight the primary machine for communication and cause a session state 5 to occur. Once the Primary gets going again it will end up causing the secondary machine to restart as well.

Is there a way to run both machines off 1 no redundant I/O server? We don't really have a need for the redundancy.