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数字计算机在化学实验室中已经很普遍了,除了数字计算之外,还大量用于实验过程的控制、数据采集,实时的或随后的实验数据处理与结果显示。在这种情况下,计算机系统必须和化学实验装置直接相连,这就是计算机的接口问题。这里,一般是指实验装置和计算机之间的数据传输问题和开关量的控制问题。数字计算机本质上只能处理时间上和幅度上都是离散的量,而实验仪器却经常以连续量作为输入信号,它的探测器所测量的量通常也是连续的,即所谓模拟量。如果用计算机控制仪器,则要求计算机给出的量必须转换成模拟量,一般是电压或电流,这一工作由数/模接口来完成。由测量单元测得的模拟量也必须转换成离散的数字量,交由计算机处理,这种转换由模/数接口完成。除此之外,为了使实验装置在规定的时刻进行规定的操作或监视工作单元的工作状态,必须有相应的开关控制接口。
Digital computers are common in chemical laboratories and, besides numerical calculations, are extensively used for experimental process control, data acquisition, real-time or subsequent experimental data processing and results display. In this case, the computer system must be directly connected with the chemical experiment device, which is a computer interface problem. Here, generally refers to the experimental device and computer data transfer between the problem and control of the switch. In essence, digital computers can only deal with discrete amounts of time and amplitude. However, experimental instruments often use continuous signals as input signals. The amount measured by their detectors is usually continuous, so-called analog. If you use a computer-controlled instrument, the amount requested from the computer must be converted into an analog quantity, typically voltage or current, which is done by the D / A interface. The analogue measured by the measuring unit must also be converted into discrete digital quantities and submitted to the computer for processing. This conversion is performed by the analog / digital interface. In addition, a corresponding switch control interface must be provided in order for the experimental device to perform the specified operation at a specified time or to monitor the operating status of the work cell.