Arrangement for controlling advancing timbering in underground mining

In an arrangement for controlling advancing timbering in an underground mine having n timbering units, comprising:

• a control unit for each of the n timbering units which can be selected individually, each control unit containing an evaluation circuit;
• and a central control room equipped with:
• a system for transmitting control data delivered by a computer serially to the control units;
• a device indicating the state of the timbering;
• and an input device for selecting the computer program, the improvement comprising, in each control unit:
• (a) a first receiver coupled to receive control data having its output connected to the evaluation circuit, the input to the first receiver in the first control unit coupled to the central control room,
• (b) a first transmitter the first transmitters of the first n-1 control units having their outputs coupled via a control line to the inputs of the first receivers of the immediately following control units, each first transmitter having the output of the first receiver in its control unit as an input;
• (c) a second transmitter having its output coupled to a further line, the further line of the second transmitter in the first control unit coupled to the central control room;
• (d) a second receiver, the second receivers in the first n-1 control units having their inputs coupled to the further line which is connected to the second transmitter in the respective immediately preceding control unit;
• and
• (e) a first switch for controllably coupling said second transmitter respectively to the evaluation circuit and to the second receiver of its control unit.