无法从2-4频道和数学中获取数据

当我试图在C上使用VISA的部分示例时，从通道1获取数据是可以的，但是当我试图从通道2-4或数学中获取前导时，我会在弹出的“查询未终止”中弹出
范围，所有值都是0 !!
我使用的代码的相关部分是：viOpenDefaultRM（＆amp; defaultRM）;
viOpen（defaultRM，sco，VI_NULL，VI_NULL，＆amp; vi）;
viClear（VI）;
viPrintf（vi，“：MEASURE：CHANnel2  n”）;
viPrintf（vi，“：DIGItiZE CHAN2  n”）;
viPrintf（vi，“：WAVEFORM：POINTS 100  n”）;
viQueryf（vi，“：WAVEFORM：PREAMBLE？ n”，“％，10lf  n”，序言）;
printf（“Preamble FORMAT：％e  n”，序言[0]）;
printf（“Preamble TYPE：％e  n”，序言[1]）;
printf（“Preamble POINTS：％e  n”，序言[2]）;
printf（“Preamble COUNT：％e  n”，序言[3]）;
printf（“Preamble XINCREMENT：％e  n”，序言[4]）;
printf（“Preamble XORIGIN：％e  n”，序言[5]）;
printf（“Preamble XREFERENCE：％e  n”，序言[6]）;
printf（“Preamble YINCREMENT：％e  n”，序言[7]）;
printf（“Preamble YORIGIN：％e  n”，序言[8]）;
printf（“Preamble YREFERENCE：％e  n”，序言[9]）;
viClose（VI）;
viClose（defaultRM）;
感谢名单！



     以下为原文

  When i'm trying to use parts of the example of VISA on C, acquiring data from channel 1 is ok but when im trying to get the preambles from channels 2-4 or Math, i get a "Query Unterminated" pop up on the scope, and all the values are 0!!

the relevant part of the code i use is:

viOpenDefaultRM(&defaultRM);
viOpen(defaultRM, sco, VI_NULL,VI_NULL, &vi);

viClear(vi);

viPrintf(vi, ":MEASURE: CHANnel2n");

viPrintf(vi, ":DIGITIZE CHAN2n");
viPrintf(vi, ":WAVEFORM:POINTS 100n");
viQueryf(vi, ":WAVEFORM:PREAMBLE?n", "%,10lfn", preamble);


printf("Preamble FORMAT: %en", preamble[0]);
printf("Preamble TYPE: %en", preamble[1]);
printf("Preamble POINTS: %en", preamble[2]);
printf("Preamble COUNT: %en", preamble[3]);
printf("Preamble XINCREMENT: %en", preamble[4]);
printf("Preamble XORIGIN: %en", preamble[5]);
printf("Preamble XREFERENCE: %en", preamble[6]);
printf("Preamble YINCREMENT: %en", preamble[7]);
printf("Preamble YORIGIN: %en", preamble[8]);
printf("Preamble YREFERENCE: %en", preamble[9]);

viClose(vi);
viClose(defaultRM);



Thanx!