Controller and I/O
To minimize process disruption, download I/O components at the lowest
level that downloads the desired changes. For example, if you add or modify a
card, download only the card rather than downloading the whole I/O subsystem or
the whole controller. By referencing the hierarchy in DeltaV Explorer, you can
determine the lowest level object to download. Expand the hierarchy (click the
+ next to an object) and download the lowest
level object with a blue triangle (
) next to it.
To preserve outputs during a download, a module-level download that includes AO, DO, Loop, and Device Control is partial.
CAUTION!For blocks assigned to non-bus I/O cards (excluding Provox and RS3 I/O), only the channels that have been modified will be affected by a download. All other channels will hold their values and status during the download to prevent disruption to the I/O. For blocks tied to bus cards (AS-I, DeviceNet, H1 fieldbus, Profibus DP, Serial), a download can potentially bump the I/O and cause the controller to hold values. To prevent bumped I/O or held values during a download, place the block producing the output in Manual mode before downloading. Be sure to determine if the process can withstand this temporary disruption. To ensure the safety of the process, it might be necessary to delay the download of the configuration changes until the process can be shut down.
Downloading loaded Phases or an SFC that has undergone a structural change can cause the controller memory to fragment. In this situation FREMEM remains constant but the largest contiguous portion of memory decreases. Typically, controller performance is not significantly affected unless several downloads of this type are performed. To prevent any impact on controller performance, do not download to loaded phases.