System Description

SystemDescriptionandInstallationManualforRangeFinder ICD1000001
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Table82PacketStructure
MessageField FieldDescription Number
bytes
StartByte Precedesallmessageswithafixedvalueof0xAA. 1
MessageType Definesthemessagetype. 1
MessageID Containsanarbitrarynumberbetween0and255(inclusive)thatuniquely
identifiesthemessage.(Typically,asequencenumber.)Acknowledgement
messagesincludetheMessageIDofthecommandmessagebeing
acknowledged.Sagetechrecomm endsincrementingthisfieldbyonewitheach
messagesent.
1
Payload
Length
IndicatesthenumberofbytesinthePayloadDatafield. 1
PayloadData Avariablelengthfieldwithadifferentlengthdependinguponthespecific
message.ThenumberofbytesinthePayloadDatamustmatchthePayload
Lengthfield.ThePayloadDatacontainstheinformationthatisusedtocontrol
andcommandtheRangeFinder.Themostsignificantbyte(MSB)ofanydata
fieldistransmittedfirst.
0to255
Checksum Containstheregular8bitarithmeticsummationofthemessagestartingwith
theStartByteandendingwiththelastbyteofthePayloadData.The
summationisperformedassumingallbytesareunsigned,andtheresultis
truncatedtotheleastsignificant8bits.
1
8.2 OperatingModes
TheRangeFindercanoperateinthefollowingmodes:
OFFInthismodethereisnocommunicationofanykind.TheRangeFinderdeviceconsumesnearzero
power.ThismodeissetusingtheMXPowerControlpinonthemainconnector.(SeeSection7.1)
STBY Standby: In this mode, transmitting is unavailable and receiving is available. In Standby, Range
Finder is in low power mode with minimal components active, including the microprocessor and
communicationports.STBYissetusingtheOperatingMessage.(SeeSection8.3.4)
ON In this mode the Range Finder is fully functional.ON is
set using the Operating Message. (See
Section8.3.4)