Knowledge Base

The attached document contains both the results of the validation tests and, importantly, tips and tricks for the developer. The equipment used with the Sofrel OPC server are RTU’s (remote telemetry units) rather than a conventional PLC. For this reason the behavior of the Sofrel OPC server is different to a conventional OPC server.

1. Data changes from an RTU are only sent to the OPC client under the following conditions.
   In response to a value refresh request from the OPC client by forcing the value of a specific mapped item.
   If one or more alarms have been reported by an RTU.
2. Items other than those used to control communication and data exchanges, cannot be browsed as simple items in the OPC Server address space. You have to use array items either with array mapping or with simple item mapping.

In addition to the results of the Validation Tests this article also contains the following useful files.

• Configuration of the OPC server – SofrelTelemetryOPCServer.XML
• Configuration of the RTU used in the tests – S550_Configuration.ICA
• SCADA Basic program used to control data refresh – Sofrel.prg
• PcVue test project – SV_SampleSofrel.zip

Download attachments:

• SofrelTelemetryOPCServer.xml.txt
• S550_Configuration.ica
• Sofrel.prg
• SV_SampleSofrel.zip
• OPCServerValidation_Sofrel_OPCServer.pdf