Owner's manual

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N 440User ual
7430‐0131‐01Rev.F
Page65
AV Man
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Chapter9. Communicatingwiththe440SeriesUnits
CommunicationCommands
Communicationcommandsareusedtoverifyaunitispresentandalive.
PingCommand
Table14PingCommand
Ping(‘PK’=0x504B)
Preamble PacketType Length Termination
0x5555 0x504B ‐ ‐
Thepingcommandhasnopayload.Sendingthepingcommandwillcausetheunittosendapingresponse.To
thandCRCfieldsarenotrequired.
facilitatehumaninputfromaterminal,theleng
Example:0x5555504B009ef4or0x5555504B
PingResponse
Table15PingResponse
Ping(‘PK’=0x504B)
Preamble PacketType Length Termination
0x5555 0x504B 0x00 <CRC(U2)>
Theunitwillsendthispacketinresponsetoapingcommand.
EchoCommand
Table16Echo
Echo(‘CH’=0x4348)
Preamble PacketType Length Payload Termination
0x5555 0x4348 N <echopayload> <CRC(U2)>
Theechocommandallowstestingandverificationofthecommunicationlink.Theunitwillrespondwithanecho
responsecontainingthe
echodata.TheechodataisNbyteslong.
EchoResponse
Table17EchoPayload
EchoPayloadContents
Byte
ffset
O
Name Format Scaling Units Description
0 echoData0 U1 — — firstbyteofechodata
1 echoData1 U1 — — Secondbyteofechodata
… … U1 — — Echodata