这是我第一次尝试使用Pyvisa，以便使用RS232连接(使用USB端口)与Agilent 34970A进行通信。在

这就是发生在我身上的事情，插入基本的第一行：IN: import visa

IN: rm=visa.ResourceManager()

IN: print rm.list_resources()

(u'ASRL4::INSTR',)

IN: inst=rm.open_resource("ASRL4::INSTR")

IN: print inst.query("*IDN?")

Traceback (most recent call last):

File "", line 1, in

File "C:\Anaconda2\lib\site-packages\pyvisa-1.8-py2.7.egg\pyvisa\resources\messagebased.py", line 407, in query

return self.read()

File "C:\Anaconda2\lib\site-packages\pyvisa-1.8-py2.7.egg\pyvisa\resources\messagebased.py", line 332, in read

message = self.read_raw().decode(enco)

File "C:\Anaconda2\lib\site-packages\pyvisa-1.8-py2.7.egg\pyvisa\resources\messagebased.py", line 306, in read_raw

chunk, status = self.visalib.read(self.session, size)

File "C:\Anaconda2\lib\site-packages\pyvisa-1.8-py2.7.egg\pyvisa\ctwrapper\functions.py", line 1582, in read

ret = library.viRead(session, buffer, count, byref(return_count))

File "C:\Anaconda2\lib\site-packages\pyvisa-1.8-py2.7.egg\pyvisa\ctwrapper\highlevel.py", line 188, in _return_handler

raise errors.VisaIOError(ret_value)pyvisa.errors.VisaIOError: VI_ERROR_TMO (-1073807339): Timeout expired before operation completed.

每次我试图读取值时都会发生超时错误。我也施加了一个更大的暂停，但什么也没有，我等了几分钟徒劳。对这个问题有什么想法吗？在