NCR RealScan 7837-3000 - Page 51

Chapter 2: Terminal Interfaces 2-13
Escapecommandsareaddressedtothesourcescannerthroughthe
“ApplicationWorkGroups.”Onceacommandissent,allscannersina
grouprespondtothatcommand.Becauseofthissituation,itis
recommendedthateachscannerbeassignedtoitsowngroup.
Thecommandstowhichthescannerrespondsare
listedoninChapter
2.The<ESC>isa1Binhexadecim al.Atypicalcommandstringisy
<ESC>x,where“y”istheapplicationworkgroupnumber,“<ESC>x”
istheescapecommandandthe
commaistheterminator.
Commandsmaybestrungtogethertocreatecustomresponse
sequences.Anexampleofacommandstringislistedbelow.
0<ESC>4<ESC>5<ESC>6,
Theaboveexamplemakesascannerinapplicationworkgroupzero
beeplow,medium,high .
OnceHostACKisenabled,thesystemworksasfollows:
• Thescannerreadsacodeandsendsdatatothebase/host
system.Noaudibleorvisualindicationisemitteduntilyou
receiveanescapecommand.
Thescannerreadillumination
goesoutuponasuccessfulread.
• Scannerissuspendeduntil
1)avalidescapestringisreceivedfromthehostsystem
(throughthebase)or
2)thescanner“timesout.”
• Oncecondition1or2abovehasbeenmet,thescannerisready
to
scanagainandtheprocessrepeats.
Timeoutisindicatedbythreerapidbeepsatthesamepitch.Atimeout
occursifthesourcescannerdoesnotreceiveavalidescapecommand
in10seconds.Ifatimeoutoccurs,theoperatorshouldcheckthehost
systemtounderstandwhy
aresponsetothescannerwasnotreceived.