.To keep a persistent copy of cached device data,
you can save the I/O Server's cache to disk. For every [IOServer]SavePeriod, the data is saved to s,
one for each cached device.
Saving the data to disk will, in most
circumstances, allow you to shut down and restart the I/O Server
without having to contact each I/O Device again to get its current
values. Instead, you can read the values from the device's
persistence
cache.
Note: When read-through caching is enabled
for a remote or scheduled I/O Device, the persistence cache for
that device is saved to disk when the active I/O Server disconnects
from the device. This occurs regardless of the value set in
[IOServer]SavePeriod. You can
enable read-through caching by setting the parameter [Dial]ReadThroughCache.
See Also