| 摘要 |
A plurality of movable storage units each have a reversible motor for driving them in the proper direction in response to a user command to open an aisle between selected units. There is a microprocessor-based programmable control module on each unit and there is a structurally similar module that acts as a system controller. Four control lines interconnect the modules. One line is for sending digital command data away from the system controller and another is for sending sensing data toward the system controller. Another line is for resync pulses transmitted from the system controller to the microprocessors simultaneously. The processor in each module responds to a resync pulse by initiating definition of a specific number of time slots for containing individual high or low bits to enable serial transmission of encoded data representative of commands and sensed conditions. The modules on each unit interpret or sense such conditions as to whether their start pushbutton has been pressed, whether their limit switches are closed to indicate proximity with another unit and whether a safety switch is open or closed. This and other sensed information is sent serially to the system controller in serial form for being interpreted and the system controller sends back commands for enabling the unit modules to interpret the direction and limits of unit movement.
|
