How could i play svf file correctly ?

Hi folks,
When trying to execute my SVF file , Impact software provided by
Xilinx issues errors like :

ScanDR 32 TDI(00000000) TDO(F286E093) Mask(0FFFFFFF) Smask(FFFFFFFF)
ERROR:iMPACT - Failed ScanDR: TDO does not match Expected TDO
ERROR:iMPACT - TDO ReadBack
: 00000001
ERROR:iMPACT - TDO Expected
: f286e093
EXCEPTION:iMPACT:SVFReader.c:335:1.20.14.1 - Scan Data Mismatch.
INFO:iMPACT:2146 - Play svf failed.
PROGRESS_END - End Operation.
Elapsed time =      1 sec.11111

Moreover i want to want to know why within SVF file the ID check
instruction is executed twice ? one with MASK and  other one  without
MASK ? This conecrns also HIR,TIR,HDR,TDR  instructions :

//Loading device with 'idcode' instruction.
SIR 10 TDI (03c9) SMASK (03ff) ;
SDR 32 TDI (00000000) SMASK (ffffffff) TDO (f286e093) MASK
(0fffffff) ;
TIR 0 ;
HIR 0 ;
TDR 0 ;
HDR 0 ;
TIR 0 ;
HIR 0 ;
TDR 0 ;
HDR 0 ;
TIR 0 ;
HIR 0 ;
HDR 0 ;
TDR 0 ;
//Loading device with 'idcode' instruction.
SIR 10 TDI (03c9) ;
SDR 32 TDI (00000000) TDO (f286e093) ;