| 摘要 |
A latching interface is provided between a machine and a monitoring or control system for the machine to latch the machine in a mode that is safe for the machine and for operating personnel upon power loss. The interface includes one or more latching relay switches, connected into one or more input signal circuits, that may be selectively set and reset by an interface microprocessor to actuate or deactuate the machine from performing certain functions. The interface microprocessor is programmable to set or reset the latching relay switches in response to a signal from a power loss sensor indicating that power to a monitor/controller device, that monitors and controls the functions of the machine, has been interrupted. The interface system further includes a power feed circuit to provide a back-up power supply to power the interface microprocessor during setting and resetting of the latching relay switches to the safe mode upon loss of normal power. Alternately, a solid state switch in series with an additional latching relay switch is connected into the input signal circuit in parallel with one or more of the latching relay switches. During normal operations, the interface microprocessor may operate these solid state switches in response to signals from the monitor/controller to control normal operating modes or functions of the machine. Upon power loss, the interface microprocessor opens the latching relay switch in series with each solid state switch and operates the parallel latching relay switch to place and keep the machine in a safe operating mode.
|
