Book Numbers are added to the store or deleted by a numericalkeyboard.
图书号码可以通过数字键盘加入存储器内，或者删掉。
2
An input device, sometimes part of a standard typewriter keyboard, consisting of a separate grid of numerical and function keys arranged for efficient data entry.
一种输入设备，有时是指标准打字机键盘的一部分，包括一个单独的用于有效数据输入的数字和功能键网格。
3
This article introduced the numerical control piano keyboard machine discussed, PLC servo system working principle, design of hardware and software of the whole system.