MATLAB串口开关问题

xiannvjiejie

先描述下问题现象：
9 b! S2 M+ D5 E        正常打开关闭一次串口后，再次打开串口提示：
       打开失败: Cannot connect to the COM31port. Possible reasons are another application is connected to the port or the port does not exist. 出错 MSerialV1>pbOpenAndClose_Callback(line 122)    fopen(s);

确认该串口没有在其它程序中使用！
: L! O( `& j; {  O( ~2 {
  {& ]' m2 o$ y; d6 K* n以下是程序代码

set(handles.pmComPort,'String',seriallist);
/ I  i% ~8 k+ H4 H8 PindexCom = get(handles.pmComPort,'Value');
' h5 m/ j! g6 R; R  u3 m/ wstrCom = get(handles.pmComPort,'String');
if indexCom > 1
    comPort = strCom(indexCom);
  f% v& E4 }6 z  [, a6 o8 Velse
    comPort = strCom;   
2 J$ z, W9 L# Eend
s = serial(comPort);
) n: d" C5 d. H5 }5 h  iif handles.pbOpenAndClose.String == "打开"
    handles.pbOpenAndClose.String = "关闭";
- C" E* g" R: v3 L- z: I5 ^    handles.pbOpenAndClose.BackgroundColor = 'g';
    fopen(s);   
else
    handles.pbOpenAndClose.String = "打开";
, q' D# }# [/ B: s    handles.pbOpenAndClose.BackgroundColor = 'r';
    fclose(s);
- N2 J0 O5 v8 @, n, t    delete(s);
' o) Q* h/ P# K) X' V0 B; d/ h" o    clear s;
end

finishedabc

试试过程中用指令能否正常退出串口，关闭串口