What is a Persisted Memory IO Device in Vijeo Citect.
With the release of V7.20, a feature called persistence can be applied to I/O devices. When implemented, the tag cache for an
I/O device is written to an XML file at a set period, allowing the last available data to be reloaded following a shutdown.
Persistence is enabled using the Persist field in the extended section of the I/O Devices Properties dialog.
You can also create a persisted memory I/O device using the Express Communications Wizard. When this type of device is
selected, the wizard creates a new I/O device with the Address and Port Name properties left blank, Memory set to “TRUE”, and Persist set
to “TRUE”. The File Name field is left empty to allow runtime to generate a default cache file name. This file will be located in the [DATA] directory.