This code system http://hl7.org/fhir/metric-operational-status defines the following codes:

CodeDisplayDefinition
on OnThe DeviceMetric is operating and will generate Observations.
off OffThe DeviceMetric is not operating.
standby StandbyThe DeviceMetric is operating, but will not generate any Observations.
entered-in-error Entered In ErrorThe DeviceMetric was entered in error.
<status value="active"/><experimental value="false"/><date value="2021-01-05T10:01:24+11:00"/><publisher value="HL7 (FHIR Project)"/><contact><telecom><system value="url"/><value value="http://hl7.org/fhir"/></telecom><telecom><system value="email"/><value value="fhir@lists.hl7.org"/></telecom></contact><description value="Describes the operational status of the DeviceMetric."/><jurisdiction><coding><system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/><code value="001"/><display value="World"/></coding></jurisdiction><caseSensitive value="true"/><valueSet value="http://hl7.org/fhir/ValueSet/metric-operational-status"/><content value="complete"/><concept><code value="on"/><display value="On"/><definition value="The DeviceMetric is operating and will generate Observations."/></concept><concept><code value="off"/><display value="Off"/><definition value="The DeviceMetric is not operating."/></concept><concept><code value="standby"/><display value="Standby"/><definition value="The DeviceMetric is operating, but will not generate any Observations."/></concept><concept><code value="entered-in-error"/><display value="Entered In Error"/><definition value="The DeviceMetric was entered in error."/></concept></CodeSystem>