特殊用法absolute position readout1.绝对位置读数器alphanumeric readout1.字母数字读出direct readout1.直接读出2.直读装置double readout1.加倍读出electronic position readouts1.电子位置读数器sum readout1.和数读出; 总数读出; 和数输出visual readout1.目视读出