Product specifications

CDM-800 Gateway Router Revision 1
Serial-based Remote Product Management MN-CDM800
6–3
When the user ‐supplied terminal emulator program is configured correctly, upon power‐up of the CDM‐800, the CLI Info Screen
appears, followed by the CLI command prompt CDM‐800>. From here, type “help[cr]” or “?[cr]” (without the quotes) to display the
CDM‐800availablecommandsandqueries,andtoreviewinstru
ctionsforusingtheinterface.
6.2 Remote Commands and Queries Overview
6.2.1 Basic Protocol
InanEIA‐232configuration,theControllerdeviceisconnecteddirectlytotheTargetdeviceviaatwowire‐plus‐groundconnection.Alldata
is transmitted in framed packets as asynchronous se rial characters, suitable for transmission and rec eption to the Controller using a
universalasynchronousreceiver/tran sm itter(UART).Controller‐to‐TargetdataiscarriedviaEI
A‐232electricallevelsononeconductor,and
Target‐to‐Controllerdataiscarriedintheotherdirectionontheotherconduc t or:
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• Controller‐to‐Target:TheControllerdevice(e.g.,theuserPC/CLI)isusedtotransmitinstructions(commands)to–ortorequest
informationfrom(queries)–theTargetdevice(i
.e.,theCDM‐800).
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• Target‐to‐Controller:The Target,inreturn,onlytransmitsresponseinformationtotheControllerwhenspecificallydirectedby
theController.

ForSerialRemoteControl,allissuedcommands(Controller‐to‐Target) requirearesponse(Target‐to‐Controller).Thisresponseiseither
to return da
ta that has been querie
d by the Controller, or to confirm the Target’s receipt of a command to change the Target’s
configuration.
6.2.2 Packet Structure
The exchange of information is transmitted, Controller‐to‐Target and Target‐to‐Controller, in packets. Each packet contains  a finite
numberofbytesconsistingofprintableASCIIcharacters,excludingASCIIcode127(DELETE).

Inthiscontext,theCarriageReturnandLineFeedcharactersareconsideredprintable.Withoneexception,allmessagesfromCont
roller‐
to‐Targetrequirearesponse–thiswillbeeithertoreturndatathathasbeenrequestedbytheController,ortoacknowledgereceptionofan
instructiontochangetheconfigurationoftheTarget.
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