| 摘要 |
An apparatus for monitoring the state of a remotely controlled means, e.g. a points drive for the points of a railway, or a signal lamp along a railway, without erroneous monitoring results occuring should the lines between a controlling means and the remotely controlled device be incorrectly connected. The remotely controlled device includes one or more special encoding means (4a, 4b, 4). Each such means gives rise to a pulse pattern which is characteristic for the means in a current which flows through it. It can thus be decided at the controlling means whether a current through it also flows through a given conductor part at the remotely controlled device. In accordance with a first embodiment, one of two different encoding means (4a, 4b) is connected into a current path in response to which of two different states a remotely controlled device assumes. According to a second embodiment an encoding means (4) is always connected in series with the remotely controlled device (6), the pulse pattern occuring when the remotely controlled device is supplied with current. |
