Siemens S7-1200 System Manual page 399

Network 6 A positive signal edge DataLogOpen REQ input simulates the user pushing a
button on an HMI that opens a data log file. If you open a Data log file that has all records
filled with process data, then the next DataLogWrite operation will overwrite the oldest
record. You may want to preserve the old Data log and instead create a new data log, as
shown in network 7.
Network 7 The ID parameter is an IN/OUT type. First, you supply the ID value of the existing
Data log whose structure you want to copy. After the DataLogNewFile operation is complete,
a new and unique ID value for the new Data log is written back to the ID reference location.
The required DONE bit = TRUE capture is not shown, refer to networks 1, 2, and 4 for an
example of DONE bit logic.
S7-1200 Programmable controller
System Manual, 03/2014, A5E02486680-AG
Extended instructions
8.7 Recipes and Data logs
399