E3631A-GPIB编程-蜂鸣和冻结显示错误该怎么办？

嗨，我正在使用matlab中的GPIB（Agilent 82357A GPIB-USB适配器）编程E3631A。
在for循环中测试函数期间，我发现（1）电源偶尔会发出蜂鸣声，虽然没有抛出错误（通过'SYST：ERR' - >测试：'没有错误'测试）（2）之后
几百次执行matlab因fopen期间超时而引发错误“警告：GPIB：AGILENT：发生超时。错误可能是由于设备地址或状态错误。”然后有必要按电源上的按钮获取
一个成功的再次开始。
有时甚至E3631A的显示屏也会关闭。任何暗示可能是什么？
在我的代码下面。
我试过* opc？
和轮询* opc也在代码中的某些点但是没有帮助任何一个，Amtschuk％创建GPIB对象GPIB_Addr = 5;
Board_Index = 7;
E3631A = gpib（'AGILENT'，Board_Index，GPIB_Addr）;
％Open Communication fopen（E3631A）;
％清除电源并等待待处理操作fprintf（E3631A，'* CLS'）fprintf（E3631A，'* ESE 1'）查询（E3631A，'* OPC？'）;
％设定输出端口的值fprintf（E3631A，'APPL P25V，15,0.2'）fprintf（E3631A，'OUTP ON'）％清理fclose（E3631A）删除（E3631A）清除E3631A



     以下为原文

  Hi,

I am programming a E3631A via GPIB (Agilent 82357A GPIB-USB Adapter) in Matlab. During tests of the function in a for loop I found that
(1) the power supply makes beep once in a while although no error is thrown (test via 'SYST:ERR' -> answer: 'No error')
(2) after some hundred executions matlab throws an error due to a timeout during fopen
"Warning: GPIB: AGILENT: A timeout occurred. Error could be due to bad device address or state."
Then it is necessary to press a button on the Power supply to get a successfull fopen again. Sometimes even the display of the E3631A switches off.

Any hints what that could be?
Below my code. I tried *opc? and polling *opc also at some points in the code but that didn't help either

Yours,

Amtschuk

% Create GPIB-Object
    GPIB_Addr = 5;
    Board_Index = 7;
    E3631A = gpib('AGILENT', Board_Index, GPIB_Addr);
  
% Open Communication
    fopen(E3631A);      

% Clear Power supply and wait for pending ops      
    fprintf(E3631A,'*CLS')
    fprintf(E3631A,'*ESE 1')   
    query(E3631A,'*OPC?');
   
% Set values of the output ports   
    fprintf(E3631A,'APPL P25V, 15, 0.2')   
    fprintf(E3631A,'OUTP ON')  
   
% Clean up
    fclose(E3631A)
    delete(E3631A)
    clear E3631A