Description
The "ReadTagValue" command reads the value of a tag from the system. Only the tag value and the quality are signaled.
When the tag value contains a line break (\n), the value cannot be signaled. An error is signaled.
Request
ReadTagValue <Tag>
For example: ReadTagValue Tag_1
Response
OnSuccess (or partial success):
NotifyReadTagValue <Tag> <Quality> <Value>
For example:
-
NotifyReadTagValue Tag_1 Uncertain 0 -
NotifyReadTagValue Tag_1 Good 10 -
NotifyReadTagValue Tag_1 Bad 12
OnError:
ErrorReadTagValue <Tag> <Error text>
For example:
-
ErrorReadTagValue Tag_1 Tag does not exist -
ErrorReadTagValue Tag_1 Encoding error -
ErrorReadTagValue Tag_1 Value contains newline