| 摘要 |
<p>Apparatus suitable for use with an operative system for monitoring the operational state of at least one system component such as a valve, which can adopt three possible states. The apparatus includes a state signal generator for operative association with the component and is responsive to the state of the component. The apparatus generates a first steady state signal whenever the component is in a first state, a second steady state signal when the component is in a second state and a time varying signal such as a square wave when the component is in a third state. -1a-</p> |
