|1||Shut Down (dumb mode) / RS-232 RX In (smart mode)||Set high for 1-5 sec to activate shutdown.|
|2||Line Fail (dumb mode) / RS-232 TX Out (smart mode)||On-battery power (normally low but goes high when the UPS switches to batteries)|
|3||Line Fail signal||Mains down (normally low but goes high when line fail)|
|5||Low battery signal||(normally low but goes high when low battery)|
|6||Line fail signal||Inverse of pin 2 Line Fail signal|
|7||UPS Turn-on/off signal||(on advanced UPSes only)|
|8||Unregulated +24 Vdc Out ??|
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