在SCH与PCB比较中出现如下信息:PCB Net List Errors Report - led-2.sch - Wed Dec 07 14:41:54 2011; `# J+ S; R3 K3 h 
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Design to Library Part Consistency Check( h3 `2 |" O2 v- p+ b. b7 I 
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No Library consistency checking errors.: v9 l3 N( D& r& ?4 D 
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Single/Zero Pin Net Warnings 
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3 b6 X- y# D6 `, f- Z0 cNet $$$2 has less than two pins in PCB net list file./ g8 \5 m' ]: Q# m# }; \ 
 
8 i* \' h; a' z! ~Schematic Connectivity Errors 
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1 i. P( j# y2 W! v* |2 I  U; [No connectivity errors or warnings. 
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$ ~* b1 l/ b$ @- K' m" m+ _7 {UNMATCHED NET PINS IN Schematic- Q* D7 }5 r4 r 
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$$$10827            C11.1        : P: Y5 i! j& a# n1 [7 x 
$$$2                R37.1        4 ~4 Q0 M; e9 P' P' X+ e  W: p" N 
GND-2               C11.2         
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UNMATCHED NET PINS IN PCB6 ?0 N0 B* C9 [) U" @# A 
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$$$10827            C11.2        3 T  T; p9 i! u 
$$$2                R37.1        R7.3        ; F. ^5 t6 E. j) i# ?& Y" ^ 
GND-2               C11.1        R7.2        8 [* d8 G# l+ y; v2 [- [0 O6 L- \ 
检查PCB与原理图中连接相同,但为何会这样报错? # g# m. Q9 m8 f! `6 L5 S 
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