| 摘要 |
PURPOSE:To make the confirmation of connecting state easy, by providing a control circuit which connects and displays corresponding channels, by touching a light pen to a light emitting element for input channel display and a light emitting element for output channel display. CONSTITUTION:After turning on a power switch of a keyboard switch 4, when a write switch is turned on, an input channel number display element 2a repeats illumination/extinguishment cyclically from the upper to the lower end. When a light pen 3 is touched to the I-th element, a photodetection signal is applied to a microprocessor 7 via an interface 9 and only the element 2aI is illuminated. Succeedingly, the output channel number display element 2b starts flashing and only an element 2bJ is illuminated by touching the light pen 3, the corresponding information is applied to a relay matrix via an interface 10 and inputs and outputs are connected through the operation of a relay on the cross point. |
