Set scan classes of multiple interfaces on the same node to ensure proper offsets

Discussion created by gkrueger on Aug 6, 2012
Latest reply on Aug 7, 2012 by gkrueger

Does anyone know if it is possible to set scan class offsets of multiple interfaces on a particular node so that they are relative to the nodes absolute time and not the time the interface is started?


I have a situation where I have multiple OPC interfaces on a single PI Interface node.  I would like to ensure that the scanning of the tags among the interfaces happens in a specific sequence (ie interface 1 at 5 seconds past every minute, interface 2 at 10 seconds past every minute, etc.).  It's fairly straight forward to setup offsets among multiple scan classes within a particular interface, but I haven't seen a way to have the scans start with an absolute time reference.   From what I've observed, scanning is always based off when the interface starts, which can vary (ie if the interface starts at 10:14:14 and is scanning every 10 seconds, then I'll get samples at :24, :34, etc....but if I restart the interface and it happens to start at 10:20:21, then my scans are happening at :21,:31, :41, etc.)  I'd like to be able to ensure a particular interface is always scanning at :05, :15, :25, etc.  


Thanks in advance for any info.