Two OPC servers reading the same PLC

[shawn_75]

I have a condition where I have OPCLink/Wonderware reading data from a PLC. I'd also like to be able to read the same data on a PC running Ignition Panel Edition. The Ignition PC is using OPC-UA and OPCLink is OPC-DA. The OPC-DA functionality is not included in the panel edition. Is it okay to have two different OPC servers reading the same data off one PLC? I have tested it and it seems to work fine but I'm not ready to implement this without a little feedback.

Shawn

 

[sthompson]

I have a condition where I have OPCLink/Wonderware reading data from a PLC. I'd also like to be able to read the same data on a PC running Ignition Panel Edition. The Ignition PC is using OPC-UA and OPCLink is OPC-DA. The OPC-DA functionality is not included in the panel edition. Is it okay to have two different OPC servers reading the same data off one PLC? I have tested it and it seems to work fine but I'm not ready to implement this without a little feedback.

Shawn

Which Model of PLC are you reading the Data from? The reason I ask is the PLC has to service the OPC requests, and not all PLCs handle that the same. It is certainly possible to do. We have 3 RSView32 PCs reading and writing quite a bit of Data from/to a PLC5/40 on DH+. There is some delay, but it has been working fine for well over 8 years.

Stu....

 

[shawn_75]

The PLC is a MicroLogix 1000 connected to ethernet using a 1761-NET-ENI. There is no messaging going on with this particular PLC.

Thanks,
Shawn

 

[sthompson]

The PLC is a MicroLogix 1000 connected to ethernet using a 1761-NET-ENI.

Thanks,
Shawn

I suspect like the SLC, there is only one Processor to handle everything, Including I/O Updated, PLC Scan, Communications, and Housekeeping. The 1761-NET-ENI also has a reputation for limited connections, and Communications issues. If you do a search on here, you will find several Threads on the subject.

Stu....

 

[shawn_75]

I've had little problems with my ENI modules and I have LOTS of them. I've found that as long as the ground wire is connected and, if it is a series d, that the firmware is 3.22, they have been quite reliable. I find myself restarting OPCLink to correct problems more often than resetting ENI modules. I am happy to hear that it is possible to do what I want to do.

Thanks,
Shawn

 

[sthompson]

I've had little problems with my ENI modules and I have LOTS of them. I've found that as long as the ground wire is connected and, if it is a series d, that the firmware is 3.22, they have been quite reliable. I find myself restarting OPCLink to correct problems more often than resetting ENI modules. I am happy to hear that it is possible to do what I want to do.

Thanks,
Shawn

Sounds good. If your ENI is dependable, and it is a reasonable amount of Data, it should work fine. Good luck.

Stu....