Method and system for safety monitored terminal block

• US 8,285,402 B2
• Filed: 07/14/2008
• Issued: 10/09/2012
• Est. Priority Date: 07/14/2008
• Status: Expired due to Fees

• Current Assignee: GE Fanuc Intelligent Platforms Incorporated (Emerson Electric Company)
• Original Assignee: GE Intelligent Platforms Incorporated (Emerson Electric Company)
• Inventors: Lueckenbach, William Henry, Thurnau, Edwin, Van Helten, Marcel
• Primary Examiner(s): ROBERTSON, DAVID
• Application Number:
  US12/172,286
• Publication Number:
  US 20100010642A1
• Time in Patent Office: 1,548 Days
• Field of Search: 700/79, 700/80, 200/401, 340/500, 361/1, 361/23, 361/52, 307/326
• US Class Current: 700/79
• CPC Class Codes: G05B 19/0425 Safety, monitoring

Abstract

A method, apparatus, and system for controlling a process are provided. The control device apparatus includes an input section configured to receive input signals from a controlled process, a first output section communicatively coupled to the input section wherein the first output section is configured to transmit the received input signals to a controller, and a second output section communicatively coupled to the controller, the second output section is configured to transmit control signals from the controller to the controlled process. The apparatus further includes a safety logic block communicatively coupled to the input section in parallel with the received input signals that are transmitted to the controller, the safety logic block is configured to generate a safety output signal using the received input signals, the safety logic block is further configured to transmit the safety output signal to the controlled process independent of the control signals.

Claims

1. A control device comprising:

an input section configured to receive input signals from a controlled process;

a controller connected communicatively coupled to the input section and configured to receive the input signal and in response generate a control signal using the input signals;

an input output termination device coupled to the input section and the controller, the input output termination device having a safety device, the safety device comprising;

at least one safety logic block;

a terminal block having at least two communication paths;

a safety output section communicatively coupled to the at least one safety logic block, the safety output section configured to transmit a safety output signal to the controlled process; and

a control output section communicatively coupled to the controller, the control output section configured to transmit control signals from the controller to the controlled process;

wherein the input signal from the controller process is bifurcated in the terminal block to a first path signal and a second path signal;

wherein the at least one safety logic block receives the first path signal and in response generates a safety output signal, and wherein the second path signal is received by the controller in parallel with the first path signal, the second path signal bypassing the safety device;

wherein the at least one safety logic block is configured to transmit a safety output signal to the controlled process independent of the control signals that are transmitted from the controller to the controlled processes;

wherein the at least one safety logic block comprises precompiled safety certifiable logic; and

wherein the at least one safety logic block comprises a plurality of safety logic blocks, wherein an output of a first of the plurality of safety logic blocks is coupled to an input of a second of the plurality of safety logic blocks.

2. A control device in accordance with claim 1 wherein the safety output signal corresponds to the precompiled safety certifiable logic and wherein the safety output signal arrives at the controlled process prior to a control signal corresponding to the precompiled safety certifiable logic.

3. A control device in accordance with claim 2 wherein the precompiled safety certifiable logic comprises at least one of a machine emergency stop and a process shutdown.

4. A control device in accordance with claim 1 wherein said safety logic block comprises a programmable logic device.

5. A control device in accordance with claim 4 wherein said safety logic block comprises a complex programmable logic device.

6. A control device in accordance with claim 4 wherein said precompiled safety certifiable logic is stored within the programmable logic device, and said precompiled safety certifiable logic is safety certifiable to verify that contents of the programmable logic device were not changed during the transmission and storage to the safety logic block.

7. A control device in accordance with claim 6 wherein safety certification of the precompiled safety certifiable logic comprises use of a cyclic redundancy code.

8. A control device in accordance with claim 1 wherein said safety logic block is mounted physically remotely from the controller.

9. A method of controlling a process, said method comprising:

receiving an input signal from the controlled process relating to a safety function of the process;

transmitting the input signal to a process controller that is remote from the process;

simultaneously transmitting the input signal to an input output termination device which is coupled to the process controller and local to the process, and comprises at least one safety logic block and a terminal block having at least two communication paths;

bifurcating the input signal using the terminal block into a first signal path and a second signal path process controller;

receiving the first signal path to the at least one safety logic block, and receiving the second signal path by the process controller in parallel;

generating, by a first safety logic block, an output signal that controls the safety function using the input signal; and

transmitting the output signal to the controlled process independent of any control signal transmitted to the controlled process from the process controller;

wherein the at least one safety logic block comprises precompiled safety certifiable logic; and

wherein said at least one safety logic block comprises a plurality of safety logic blocks in a programmable logic device, said method further comprising receiving by a second safety logic block, the output signal generated by the first safety logic block, said second safety logic block generating a second output signal that controls the safety function using the input signal and the second output signal.

10. A method in accordance with claim 9 wherein the input signal is processed in the process controller in parallel with the at least one of the plurality of safety logic blocks.

11. A method in accordance with claim 9 further comprising generating, in the controller, a control signal that controls the safety function using the input signal wherein the output signal generated by said first safety logic block arrives at the process before control signal transmitted to the controlled process from the controller.