公开(公告)号：US5541904A

公开(公告)日：1996-07-30

申请号：US458476

申请日：1995-06-02

申请人： Barry A. Fite ,  Michael L. Mitchell ,  Russ A. Kunz ,  Clifford R. Brannon

发明人： Barry A. Fite ,  Michael L. Mitchell ,  Russ A. Kunz ,  Clifford R. Brannon

IPC分类号： G06F1/00 ,  G06F21/00 ,  G06K1/12 ,  G06K19/14 ,  G11B7/0037 ,  G11B7/005 ,  G11B7/24 ,  G11B7/26 ,  G11B20/00 ,  G11B23/28 ,  G11B23/36 ,  G11B23/38 ,  G11B27/10 ,  G11B27/24 ,  G11B7/00

CPC分类号： G11B20/00326 ,  G06F21/00 ,  G06K1/126 ,  G06K19/14 ,  G11B20/00086 ,  G11B20/00115 ,  G11B20/00123 ,  G11B20/0021 ,  G11B20/00246 ,  G11B20/0026 ,  G11B20/00557 ,  G11B20/00695 ,  G11B20/00876 ,  G11B20/00927 ,  G11B23/281 ,  G11B23/284 ,  G11B23/36 ,  G11B23/38 ,  G11B27/105 ,  G11B27/24 ,  G11B7/005 ,  G11B7/24 ,  G11B7/26 ,  G11B7/0037

摘要： A machine-readable serial number is formed on a CD-ROM by using a laser to selectively remove a reflective layer from the CD-ROM. Removal of the reflective layer creates defects in addressable information storage locations on the CD-ROM. The serial number is read by detecting the defects. The serial number is used in a software distribution system in which many different software programs are distributed on a single CD-ROM and an access code based on the desired software program and the serial number of a particular CD-ROM is used to "unlock" the desired program on the particular CD-ROM.

公开(公告)号：US5150363A

公开(公告)日：1992-09-22

申请号：US392417

申请日：1989-08-11

申请人： Michael L. Mitchell

发明人： Michael L. Mitchell

IPC分类号： H04L5/16

CPC分类号： H04L5/16

摘要： Serial input/output multiplexing apparatus for bi-directional communication of input status signals and output control signals between remote devices and a programmable logic controller (P.L.C.) over a two-wire, asynchronous communication channel. A remote module includes an input interface circuit to receive input status signals from each of plural input devices, an output interface circuit for transmitting output control signals to each of plural output devices, and a controller for selectively coupling the input interface circuit or the output interface circuit to the two-wire asynchronous communication channel for transmitting serial status information to the communication channel or for supplying to the output interface circuit output control information serially received from the communication channel. A local module includes a local output interface circuit for applying the status information to the P.L.C., a local input interface circuit for receiving control information from the P.L.C. and a controller for selectively coupling the local output or input interface circuits to the communication channel for receiving status information or transmitting control information.

摘要翻译： 串行输入/输出复用装置，用于通过双线异步通信信道在远程设备和可编程逻辑控制器（P.L.C.）之间进行输入状态信号和输出控制信号的双向通信。 远程模块包括：输入接口电路，用于从多个输入装置中的每一个接收输入状态信号;输出接口电路，用于将输出控制信号发送到多个输出装置;以及控制器，用于选择性地耦合输入接口电路或输出接口 电路连接到用于将串行状态信息发送到通信信道的二线异步通信信道或者用于向从输出接口电路输出从通信信道串行接收的输出控制信息。 本地模块包括用于将状态信息应用于P.L.C.的本地输出接口电路，本地输入接口电路用于从P.L.C.接收控制信息。 以及用于选择性地将本地输出或输入接口电路耦合到通信信道以用于接收状态信息或发送控制信息的控制器。