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Qtech Q71B Quick start guide

  • Hello! I'm ready to assist you with the Q71B Radio Modem Quick Start Guide. This document details how to connect and configure the Q71B modem for use with DATRAN RTUs, specifically the XL4 and DATRAN II eXcel models. It includes information on power connections, configuration steps, and how to tune the device for optimal performance. I've read the entire document and I'm ready to answer your questions about this device.
  • What is the supported voltage range for Q71B modem?
    What happens if the supply voltage is outside the specified range?
    Which RTU firmwares are compatible?
    What is the default transmit audio signal level of Q71B?
Q71B–1200bpsFSKRadioModem
forXL4andDATRANIIeXcelRTUs
QuickStartGuide
Q71B–QuickStartGuide–v1.0–February2013
www.qtech.co.nz Tel:033663713
Overview
TheQ71BmodemallowsyoutoconnectaDATRANRTUviaanRS232serialporttoa
DATRAN1200bpsradiocommunicationssystemusingtheV.23FSKprotocolbutwithout
the backward channel. This allows 1200bps in both directions as the modem is uses a
specialturnaroundfeature.
The Q71B interfaces to either a Tait TM81xx radio (fitted with a Q82 interface), or a
DATRANQ80telemetryradio.
TheradiotypeneedstobespecifiedsoQTechcansupplythecorrectcable.
EachQ71Bissuppliedcompletewitha1mRadiocableanda400mmRS232serialcable.
The Q71B can also simplify radio network upgrades from 300bps to 1200bps as it
removestheneedtochangetheinternalmodemhardware.
Prerequisites
TheDATRANIIeXcelmusthaveQ03firmwarev5.21orlater.
TheQ90softwarerequiredisv3.27orlater.
IfusingtheDATRANXL4RTU,allversionsarecompatible.
AllversionsofWorkbenchsoftwarearecompatible.
Q71B–QuickStartGuide–v1.0–February2013
www.qtech.co.nz Tel:033663713
PowerSupplyConnections
TheQ71Bisdesignedtooperatefromasupplyvoltageintherange8.0VDCto15.0VDC.
Asupplyvoltagegreaterthan15.0Vwillblowthe500mAfuseinsidetheQ71B.
Asupplyvoltagelessthan8.0Vwillresultindegradedorunreliableperformance.
TheDATRANXL4RTUandtheeXcel(RevD)RTUhavetwoRS232ports;bothcanuse
theQ71Bforanalogueradiocommunications.
Thesignificantdifferencebetweenthetwoports,isthatthelowerRS232port(RS232-B)
ontheQ22Dhasa+VsupDCoutputsupplyline.TheQ71Bcanbepoweredviathisline,
solongasjumperJ23ontheQ22Disinthe1-2position.RS232-Aportontheprocessor
doesnothavethissupplyline,sotheQ71Bmustbepoweredthroughthethreeterminal
powersupplyconnector,thepowersupplyconnectionsareshownonthetopcover
LeftPin
MiddlePin
RightPin
G
 PowerSupplyNegative
+ PowerSupplyPositive(8V–15VDC)
Notconnected
 
ThedefaultinstallationpositionoftheQ71BisonthelowerRS232port.
AllnewRTUswillbeconfiguredwiththecorrectjumpersettingforthis.
However,pleasecheckthisjumperonexistingRTUsbeforeusingaQ71B.
IfusingthemodemontheRS232-Aportdonotapplypowerfromboththe
portandtheexternalsupply
IftheDATRANRTUispoweredfroma24VDCsystem:
DonotconnecttheQ71Modemtothis24VDCsupply.
DonotconnecttheQ71modemtotheRS232Aport;usethe12VDCsupply
thattheradiouses&connecttotheQ71powerconnector.
Q71B–QuickStartGuide–v1.0–February2013
www.qtech.co.nz Tel:033663713
Configuration
TheDATRANIIeXcelmustbeconfiguredsothatitwillusetheQ71Bforcommunications.
PoweruptheRTUandconnectQ90softwaretotheRTU.
Navigatetothe“Communications”tabandset“DeviceType”asshownbelow.
TheupperRS232portisconfiguredinthesameway.
Q03RTUConfiguration XL4RTUConfiguration
Diagnostics
TheQ71BhasthreestatusLEDs.
PWR–Power.GreenLEDisonwhenpowerisapplied.
RX–Receive.OrangeLEDinonwhenradiomuteisactive.
TX–Transmit.OrangeLEDisonwhenRTUistransmitting.
IftheGreenPWRLEDisnotoncheckthefuse.
Tuning
Q03RTUTuning
OncetheQ03DhasbeenconfiguredtousetheQ71B,thetransmitaudiosignallevelcan
be adjusted by pressing the “Set TX Level” button in Q90. This will make the Q71B
transmitacontinuoustone,andanACvoltagemetercanbeplacedacrossthepinsofthe
connectorlabelled“LVL”intheQ71B.
Turnthepotentiometeranti-clockwisetoreducethesignallevel
Turnthepotentiometerclockwisetoincreasethesignallevel
Note–thisprocesswillhavealreadybeenperformedaspartofthefactorysetupatQTech
priortodelivery.Thedefaultlevelis-3dBm(548mV)intoa600Ωresistiveload.
XL4RTUTuning
ThisisperformedinaverysimilarmethodtotheaboveQ03processbutviaWorkbench.
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