Errrno 32 Pipe error, escpos python2

Question

>我需要测试爱普生POS打印机TM-U220PD。我通过并行转换器将其连接到我的笔记本电脑。它已完全安装，但是当我使用 python escpos 测试它时，显示以下错误：

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到并行转换器应该由您的系统安装到文件系统中（我假设您从跟踪来看，您在*nix上）。通常这类似于 /dev/usb/lp0 .

对于第一次调试，您可以尝试只写入此"文件"：

echo "Testn" > /dev/usb/lp0

如果这有效，您应该能够成功打印：

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