Refreshes the state of the client cache with the value from the specified data source. After refreshing, you can get the latest tag value by calling the GetVal method.

The client cache is refreshed periodically, at a rate determined by the PSTagUpdateRate root property.

ReadRefresh is used when you want to force a refresh of a value immediately after AddTag.

ReadRefresh allows you to specify multiple tags at once as a string array. When reading the values of multiple tags, calling ReadRefresh once will result in faster processing than calling it multiple times.

a = this.ReadRefresh( c("$D0","$D1","$D2","$D3","$D4"), "device");