Process and apparatus for the remote polling of measuring points

• US 5,583,493 A
• Filed: 08/26/1994
• Issued: 12/10/1996
• Est. Priority Date: 08/27/1993
• Status: Expired due to Term

• Current Assignee: PRÜFTECHNIK Dieter Busch AG (Fortive Corp.)
• Original Assignee: PRÜFTECHNIK Dieter Busch AG (Fortive Corp.)
• Inventors: Lysen, Heinrich
• Primary Examiner(s): Hofsass, Jeffery
• Assistant Examiner(s): Mannava, Ashok
• Application Number:
  US08/296,501
• Time in Patent Office: 837 Days
• Field of Search: 340/870.11, 340/870.06, 340/825.04, 340/825.06, 340/825.08, 340/825.57, 340/825.77, 340/870.01, 340/870.02
• US Class Current: 340/870.01
• CPC Class Codes: H04Q 9/16 by predetermined number of pulses

Abstract

A process and a device for the remote interrogation of measuring points is offered that form at least one group belonging together spatially and that supply electric measuring signals that are supplied separately to a central evaluation station. The distinction of this process and this device according to the invention is that the measuring signals from each of the measuring points forming one group are supplied in each case via an associated signal transmission device, preferably one (if necessary two-wire) line first to a network device assigned to the respective group, which holds the measuring signals receive from its measuring points for successive switching to its input and that for each network device the measuring signals are switched through control signals led via its input in a predetermined sequence to its input which is connected directly or indirectly with an input of the central evaluation station.

Claims

1. A method for the remote interrogation of measuring points that form at least one group belonging together spatially and that supply electric measuring signals with respect to specified states of monitored machines, whereby said electric measuring signals are separated from each other and are supplied to a central evaluation station, comprising:

supplying said measuring signals from each of said measuring points forming a group via a signal transmission device to a first network device assigned to said group, said first network device having one terminal for each measuring point, and having a communication means, said communication means of said first network device being capable of both receiving information and transmitting information;

switching said measuring signals of said individual measuring points for said first network device in a predetermined sequence from said terminals to said communication means of said first network device in response to control signals transmitted from a communication means of said central evaluation station, said communication means of said central evaluation station being capable of both receiving information and transmitting information to the communication means of said first network device;

supplying measuring signals from measuring points to a second network device, each of said first and second network devices having a said group of said measuring points, said first and second network devices being connected to each other in a defined sequence and wherein said first network device having an additional terminal not used for receiving a said measuring signal, and wherein said first and second network devices each further comprise a communication means;

establishing a serial connection between said additional terminal of said first network device and said communication means of said second network device after a last said measuring signal is switched from said terminal of said first network device to said communication means of said first network device; and

connecting said first network device with its said communication means to said communication means of said central evaluation station.

2. An apparatus for transmitting electric measuring signals from several measuring points via a transmission device to a central evaluation station having a communication means, said communication means of said central evaluation station suitable for both receiving information and for transmitting information, comprising:

a network device, said network device having separate terminals in communication with each of said measuring points and said network device having a communication means connected to said communication means of said central evaluation station, said communication means of said network device being suitable for both receiving information and for transmitting information and said network device having a switching device that responds to electric control signals generated by said communication means of said central evaluation station so as to connect said terminals to said communication means of said network device one after the other, so that said measuring signal from another said measuring point is applied successively to said communication means of said network device during time intervals between said control signals during any one interrogation cycle; and

said switching device has an electronic counter having a number of digits that exceeds the number of said measuring points belonging to said group by at least one place value, and said counter has a counting output connected with an additional terminal of said network device and said counter has additional counting outputs that respond sooner than said counting output during the counting function, connected in each case, via said terminals, to a measuring point whereby a power supply connection of said counter forms said communication means of said network device and said counter is wired from said communication means of said network device such that said counter is incremented by one more digit with a pulsed interruption or a clear reduction of the power supply voltage applied to said communication means of said network device and when the last said digit conducted to the communication means of said network device is reached, the continued counting stops so that any following pulsed interruptions or reductions are communicated via said counting output to another network device.

3. The apparatus in accordance with claim 2, wherein said apparatus has a plurality of network devices;

said measuring points are interconnected with said terminals of said network devices and wherein said additional terminal of one said network device is interconnected with said communication means of another said network device and said communication means of one said network device is interconnected with said communication means of the central evaluation station, in each case via a cable.

4. The apparatus in accordance with claim 3, wherein the cables are twin-wire cables.