Specifications

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14 Multi‐TechSystems,Inc.MultiModemCellUserGuide
Chapter 3 – Using the Wireless Modem
UsingATCommandstoVerifySignalStrengthandRoaming
Status
YoucanuseATcommandstooperate,configure,andqueryyourmodem.ReferenceguidesdocumenttheATcommands.
YoucandownloadtheseguidesfromtheMulti‐Techwebsite.
Toverifysignalstrengthandroamingstatus,youmustuseaterminalapplicationsuchasHyperTerminal.Toopenthis
programinWindowsXP,gotoStart>AllPr
ograms>Accessories>Communications>HyperTerminal.OtherWindows
operatingsystemshavesimilarpathstoHyperTerminal.Seeyoursystem’sonlineHelpifyoucannotfindHyperTerminal.
VerifyingSignalStrength
Toverifysignalstrength:
1. Openaterminalprogramofyourchoosing.
2. TypeAT+CSQ
Themodemrespondswiththereceivedsignalstrength(rssi)andthechannelbiterrorrate(ber).
RSSIrangesfrom0to31.
SignalStrengthVerification– RSSI
AT+CSQxxValues SignalStrength
0‐10 WeakorInsufficient
11‐20 Average
21
–
31 Exceptional
99 Nosignal
BERrangesfrom0to7(Sevenisthehighesterrorrate).
CheckingNetworkRegistrationandRoamingStatus
ToverifythattheMultiModemisregisteredonthewirelessnetwork:
1. OpenHyperTerminal.
2. TypeAT+CREG?
Themodemrespondsinoneofthefollowingways:
NetworkRegistrationVerification
Value NetworkRegistrationStatus
0,0 Themodemisnotregisteredonanynetwork
Ifnotregistered,verifythesignalstrength.Thereceivedsignalmight
notbestrongenoughforthemodemtoregister.
0,1 Themodemisregisteredonthehomenetwork.
0,5 Themodemisregisteredonanetworkanditisroaming.
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