| 摘要 |
<p>Each of the signal-generating emergency cutout switches, stop switches or position switches (10,12,14,16) is wired to two slave modules (e.g. 22,30) on independent buses (18,20) with master control modules (42,44). These perform cyclic interrogation of their slaves, and the results are compared (50). Any detected imbalance in the supply of energy from the separate power units (38,40) causes the machinery to be switched off and an alarm is generated. The master modules are also interfaced (46,48) to programmable controllers or process computers.</p> |
