Data I/O 29B, Руководство оператора

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Remote Control
leader and Null Outpu1
A leader is a string of chorocters triat Is anached to l h e beginning and end of a data Ille. It Is used
to separate dlfferent 111� from one onolher and allows extra room which may oo micossary ror
looding ond unloading ltie dale med l u rn to or from eq u i pm e n t For the 2QB. bhe leoder Is se n l at lt,,e
beglnnln� ;;md end 0: a data output operafton. Wl1h ooo e xcep t io n , this leoder wilt always be
oompri� of oorrioQe rerurn [CR]. a line feed (lF}, af\d 50 nulls in succession.
Null count Is the numbor of null cho r a ct ec-s In a si r i ng , or charoclets between each record or line
w i 1 h l n a fila Whal actualty comprises a dato record depend$ upon !he formal 1hol ts be.Ing us0d.
Records and lines con bo�ttv b8 thought of as seporatlons or oota -...,1thtn a me.
Null coont is o porame1er which con be deltnoo by lhe 29B user for use with printers wlfh o sic.,,
carriage re1um r esponse tlme. The number of null$ con be set to Orf)' valoo from 2sro 10 25a declrnOI
(FE h8XOdecirno1). W
i
th one exception. the string of charccfers ccil)Cllly seflt belweell eoch and f!o1efY
reoorc, or line of the tile includ85 a cmrtoge rerum (CR]. o li n e feed [LFJ. ar)d the number or null!>
defined by the null coont,
The exceptt.on referre<l to otiovo ror !he leader and the nu l l count occurs when ffrle user defines lhe
n u ll counf equal lo ttie value of '"Ff"• heXadeclmot (or 255 dec i ma l) . In thl$ oosa n,,e leocter Is macro
up of a solitary cc;mloge rett.Jrn (no t in e
,
feed and no ™J11$). Also. 1he string t8PQroting the reoords of
!Mi me Is a carriage tG1urn (no l ir.e feed$ ona no null�).
R:Jr'ity tor l he beginning and erld leoCler Is the some as !he parity for the daflO wllhin the fita The
$Orne Is !rue for 1tle carrla,ge tGI\Jrn [CR]. l i ne feed (HJ and nulls seporofing too record� or lin� or n�
fila They hove the some porl!y as tr10 data. However, rt $h04.Jld be noted !hot 'blnory formo-1$ (10, 1-1
ones 89) do no1 h.c:we parity lor their dalo; fheroto,e, the fOOder. the corrtoge return, tine feed. ond
fl\llls s.eporallng l t">e records IOr ttiene files have no portty.
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