Method for the provision of malfunction protection for lights in decentralized traffic-light installations

• US 5,220,321 A
• Filed: 07/01/1991
• Issued: 06/15/1993
• Est. Priority Date: 04/04/1989
• Status: Expired due to Term

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Sauer, Werner
• Primary Examiner(s): Ng, Jin F.
• Assistant Examiner(s): Hofsass, Jeffery A.
• Application Number:
  US07/721,423
• Time in Patent Office: 715 Days
• Field of Search: 340/907, 340/912, 340/931, 340/641, 340/642, 340/644, 307/39, 364/436, 364/550, 364/550.01
• US Class Current: 340/931
• CPC Class Codes: G08G 1/097 Supervising of traffic control systems, e.g. by giving an alarm if two crossing streets have green light simultaneously

Abstract

Process for signalling malfunction protection in decentralised traffic-light installations having a signalling malfunction protection (SSP) and evaluation assembly (AWP) in a node control unit (KS) and having a plurality of PLS units (PLS modules M1, M2, . . . ) which each have peripheral lamp switches and sensors and a data transceiver, which together form an LMP assembly, as well as transformers and rectifiers for associated signal generators and groups of signal generators (SG) on the respective traffic-light poles (SGM1, SGM2, . . . ). The node control unit (KS) is connected to the PLS modules (M1, M2, . . . ) with a power and a data line (EDL). In addition to the customary signalling malfunction protection, the operativeness of the individual PLS modules and LMP assemblies (M1, M2, . . . ), respectively, is cyclically tested irrespective of the momentary signalling status. With each complete telegram cycle (TZ1, TZ2, . . . ), in each case one PLS module (LMP assembly) is tested with a separate test telegram (TB) by the signalling lamps (SL) of the respective PLS module (Mn) being switched off for a very brief period (e.g. 3 ms) with the first cycle, switched to red with the second cycle, to amber with the third cycle and to green with the fourth cycle, the correct acknowledgement (RM) being monitored in the signalling malfunction protection and evaluation assembly (SAB) and, when a fault occurs, the traffic-light installation being at least partially switched off or switched to flashing amber.

Claims

1. A method for signalling malfunction protection in decentralized traffic-light installations having a signalling malfunction protection and evaluation assembly in a node control unit and having a plurality of peripheral lamp switches and sensors that form modules, and data transceivers, which together form assemblies, as well as transformers and rectifiers for associated signal generators and groups of signal generators on respective traffic-light poles, the node control unit being connected to the data transceivers of the individual assemblies via a power and a data line, comprising the steps of:

cyclically testing, in addition to signalling malfunction protection, the operativeness of individual assemblies irrespective of momentary signalling status, in each case one assembly being tested with a separate test telegram with a complete telegram cycle that addresses all assemblies, by signalling lamps of the respective module being switched off for a very brief period with a first cycle, switched to red with a second cycle, switched to amber with a third cycle and switched to green with a fourth cycle, a correct acknowledgement being monitored in the signalling malfunction protection and evaluation assembly and, when a fault occurs, the traffic light installation being at least partially switched off or switched to flashing amber.

2. The method according to claim 1, wherein the test telegram has an identifier and an item of test information, normal information for the respective assembly being transmitted into a buffer in the respective assembly and the test information being transmitted to the associated signalling lamps, and wherein at the end of all telegram cycles the normal information with test identifier, in a reset telegram, for the respective assembly is transmitted once more.

3. The method according to claim 2, wherein every assembly has a reset device which automatically transmits the normal information stored in the respective buffer of every assembly to the respective signalling lamps if the reset telegram does not occur.