Applies To:
  • CitectSCADA 5.00, 5.01, 5.10, 5.20, 5.21, 5.30, 5.31

What is the limit to the number of events that you can extract with TrnEventGetTable in Citect 5.30? It appears to be around 1006 for some unknown reason. Can you explain? 

There is an array limit in cicode of 64kb but the real limit is a client/server data transfer buffer which is set to 12,288 bytes. This allows for around 1000 event trend samples or 6000 periodic trend samples. Event samples are 12 bytes and periodic are 2 bytes, with about 200 bytes used for a header.

In version 5.31 this data transfer buffer limitation is removed (but there is still a 64 kb limit on the cicode array). Instead large data transfers will be automatically broken into smaller packets to send across the client/server interface, and then reassembled at the other end.