This read-only value defines the hysteresis margin applied around the limitHi and limitLo thresholds for a channel's limit-watching logic. Admins use it to keep an alarm from flapping rapidly near a threshold, since the reading must move back past the limit by at least this margin before the alarm condition clears. As an illustrative example, with limitHi set to 300 and limitHy set to 10, an alarm raised when the value exceeds 300 would not clear again until the value drops below 290.