Errrno 32管道错误，escpos python2

Question

我需要测试一台爱普生POS打印机TM-U220PD。我把它通过一个并行转换器连接到我的笔记本电脑上。它是完全安装的，但是当我用python escpos测试它时，它显示了以下错误：

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/escpos/escpos.py", line 437, in text
    self._raw(txt.encode())
  File "/usr/local/lib/python2.7/dist-packages/escpos/printer.py", line 85, in _raw
    self.device.write(self.out_ep, msg, self.timeout)
  File "/usr/local/lib/python2.7/dist-packages/usb/core.py", line 948, in write
    self.__get_timeout(timeout)
  File "/usr/local/lib/python2.7/dist-packages/usb/backend/libusb1.py", line 824, in bulk_write
    timeout)
  File "/usr/local/lib/python2.7/dist-packages/usb/backend/libusb1.py", line 920, in __write
    _check(retval)
  File "/usr/local/lib/python2.7/dist-packages/usb/backend/libusb1.py", line 595, in _check
    raise USBError(_strerror(ret), ret, _libusb_errno[ret])
usb.core.USBError: [Errno 32] Pipe error

这是用于测试的代码：

>>> from escpos.printer import Usb
>>> p = Usb(0x067b, 0x2305)
>>> p.open()
>>> p.text()

Answer 1

这样的USB-to-Parallel转换器应该由您的系统挂载到文件系统中(根据您的跟踪，我假设您使用的是*nix )。通常这类似于/dev/usb/lp0。

对于第一次调试，你可以试着只写这个“文件”：

echo "Test\n" > /dev/usb/lp0

如果可以，您应该能够使用以下命令成功打印：

from escpos.printer import File
p = File(devfile='/dev/usb/lp0')
p.text("some text\n")