Standalone_edc does not have a way of reporting subscribed channels that are in an error state
If a EPICS CA subscription is in a state with a status != ECA_NORMAL there is no way to tell.
This was seen with the HWS ioc. On initialization it would only partially process its database, so you could caget a channel and get a value (with an undefined status field) and the EDC would record it as 0.
It might be useful to track down issues like this to have the edc report what channels are currently giving status != ECA_NORMAL.
It should be noted that when status != ECA_NORMAL we do not have a value to collect, so our current behavior is correct as far as the data goes, this is just for diagnostics.