Considerations
Managing downloads can become more difficult the larger projects become, especially if the process that the PLC is controlling is also critical and PLC downtime is to be kept to a minimum.
Data segregation
A good method of reducing the effect of reinitialization and the chance of it needing to set the data in your project to the starting values is to segregate data into more than one data block:
Figure 13.26 – An example of segregating data
By grouping data into singular data blocks, where the data has something in common with the data it is grouped with, reinitialization only affects data that is grouped together.
Figure 13.26 shows an example of mixed data in DB1 on the left-hand side. If a variable was added, removed, or modified in this data block, the entire data block would be reinitialized. Then, groups of unrelated data would be set to the starting values.
By splitting the relative data into three data blocks, only...
