摘要:
A diffuse infrared communication link provides for communication directly between nodes each having a transceiver. A repeater may be present to facilitate communication. Each node is automatically reconfigurable between operation with or without a repeater. When a repeater is present each node automatically ignores any transmission by another node.
摘要:
A diffuse infrared communication link provides for communication directly between nodes each having a transceiver. A repeater may be present to facilitate communication. Each node is automatically reconfigurable between operation with or without a repeater. When a repeater is present each node automatically ignores any transmission by another node.
摘要:
Method and apparatus for entering control points relative to a dynagraph of a well pumping unit using the position of a beam and a pen holder of an XY plotter. The beam and/or the pen holder is physically moved to a desired location and an "enter" button is pressed to enter a value corresponding to an X or a Y position and another button is used to enter the other corresponding position value. The entered point is used to control operation of the well.
摘要:
Each of a plurality of message terminal units (10, 12, 14, 16) has a keyboard (20) for entry of data, a visual display (22) for display of entered and received data, and a logic system (FIG. 4) for processing received and transmitted messages. Each unit stores in a CPU (52) a dedicated user terminal identification. Each transmitted message is annexed to a destination terminal identification and said user terminal identification (FIG. 5). Only a unit with a stored user identification identical to the destination identification in a transmitted message can receive and display transmitted messages. Upon receipt of a message, a terminal sends an automatic response to the sending terminal, which provides an appropriate indication to the sender. The receiver can send a manual acknowledgement (42) to the sender, which causes the message to be cleared from the sender's display. The units transmit messages via pulse modulation of a high frequency carrier over a supply power line (26) so that no special wiring is required. A unit can send messages to plural destinations and indicate which destination units have received the message. Optionally, a user can store plural incoming messages (FIG. 7) and selectively display same. Also, optionally, a unit can send its user's identification indicia, upon attempted entry thereof, to all other units which will compare the attempted identification entry indicia with their stored user identification indicia (FIG. 8) and indicate if the same indicia are already in use, thereby preventing two users from using the same indicia so as to insure privacy of transmission. A unit can be made to automatically send a fixed message upon receipt of any message, this feature being most useful to indicate a user's temporary absence.
摘要:
An interface which connects input/output (I/O) controllers to a data channel in a data processing system. A bidirectional priority bus is provided interconnecting the channel with the controllers. Each controller is assigned a priority level. When a controller requires service, it signals the channel over a common request line and the channel responds with a channel select signal. Each requesting controller gates a binary number corresponding to its priority level onto the common priority bus. Contending controllers resolve priority among themselves by monitoring the priority bus. If a controller detects a higher priority level than its own level on the bus it removes its priority number from the bus. The highest priority controller then activates an acknowledge signal and places its device address on a bidirectional data bus in response to a ready signal from the channel.