Communication system with monitored input state of an input device as well as current-increasing device

• US 8,829,880 B2
• Filed: 03/21/2012
• Issued: 09/09/2014
• Est. Priority Date: 03/25/2011
• Status: Active Grant

• Current Assignee: Phoenix Contact GmbH & Company KG
• Original Assignee: Phoenix Contact GmbH & Company KG
• Inventors: Oster, Viktor
• Primary Examiner(s): BERHANE, ADOLF D
• Application Number:
  US13/426,200
• Publication Number:
  US 20120249109A1
• Time in Patent Office: 902 Days
• Field of Search: 323/265, 323/266, 323283-285, 323/299
• US Class Current: 323/299
• CPC Class Codes: H04Q 2209/88 Providing power supply at the sub-station
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

The present invention concerns a communication system with monitored input state of an input device. The input device has an input connection, a ground connection and an input circuit connected between the input connection and the ground connection. The input circuit is designed to detect an input signal. A sensor device is also provided, which is connected to the input connection and optionally the ground connection. The communication system also has a current-increasing device connected to the input connection and the ground connection, which is designed to furnish an increased current for the input circuit for an adjustable time period as a function of the voltage lying on the input connection. A power supply is also provided to supply power to the sensor device.

Claims

1. A communication system (10) for reliable detection of a contact-encumbered signal comprising:

an input device (20), which has an input connection (32), a ground connection (34) and an input circuit (70) connected between the input connection (32) and ground connection (34), which is designed to detect a contact-encumbered signal delivered by a sensor device (100),

the sensor device (100) connected to the input connection (32),

a power supply (40) to supply the sensor device (100) with power, and

a current-increasing device (80) connected to the input connection (32) and ground connection (34), which is designed to furnish an increased current for the input circuit (70) for an adjustable time period as a function of the voltage lying on the input connection (32), so that the contact-encumbered signal is reliably detectable.

2. The communication system according to claim 1 wherein the input circuit (70) has an internal resistance and that the current-increasing device (80) is designed to reduce the internal resistance of the input circuit (70) as a function of the voltage lying on the input connection (32) for an adjustable period.

3. The communication system according to claim 2 wherein the input device (20) has a power supply connection (30), to which the power supply (40) can be connected.

4. The communication system according to claim 1 wherein the current-increasing device (80) has:

a detector device (120, 122, 130), which is designed to detect the voltage between the input connection (32) and the ground connection (34), at least one switching element (126) connected to the detector device (120, 122, 130), which is designed to connect an electrical resistance element (127) with constant resistance value between the input connection (32) and ground connection (34), if the voltage between the input connection (32) and ground connection (34) has fallen below a threshold value.

5. The communication system according to claim 4 wherein the current-increasing device (80) is designed to switch the switching element (126) on or off.

6. The communication system according to claim 1 wherein the current-increasing device (80) has:

a detector device (120, 122, 130) designed to detect the voltage between the input connection (32) and the ground connection (34), and

a voltage-dependent resistance element connected to the detector device (120, 122, 130), whose resistance value is variable as a function of the voltage lying on the input connection (32).

7. The communication system according to claim 3 wherein the input device (20) has a detector device designed to detect the voltage difference between the power supply connection (30) and the input connection (32) and that the current-increasing device (80) is designed to reduce the internal resistance of the input circuit (70) as a function of the detected voltage difference for an adjustable time period.

8. The communication system according to claim 7 wherein the current increasing device (80) is designed to reduce the internal resistance by a constant value or by a value variable as a function of the detected voltage difference.

9. The communication system according claim 1 wherein the current-increasing device (80) is implemented in the input device (20) or is designed as a connectable circuit device.

10. The communication system according to claim 1 wherein the input device (20) is a memory-programmable control device.

11. A current-increasing device (80), which is designed for use in the communication system of claim 1 and designed to furnish an increased current for the input circuit (70) for an adjustable time period as a function of the voltage lying on the input connection (32), so that the contact-encumbered signal delivered by the sensor device (100) is reliably detectable.