In situ flue gas analyzer with improved process communication

Abstract

An in situ flue gas analyzer includes a probe extendable into a flue. The probe has a measurement cell providing a signal responsive to a concentration of a gas within the flue. A controller is coupled to the probe and configured to provide an output based on the signal from the measurement cell. A first media access unit is coupled to the controller and is operably coupleable to a first process communication link. The first media access unit is configured to communicate in accordance with an all-digital process communication protocol. A second media access unit is coupled to the controller and is operably coupleable to a second process communication link. The second media access unit is configured to communicate in accordance with a second process communication protocol that is different than the all-digital process communication protocol. The first and second media access units are enabled simultaneously.

What is claimed is: 
     
         1 . An in situ flue gas analyzer comprising:
 a probe extendable into a flue, the probe having a measurement cell providing a signal responsive to a concentration of a gas within the flue;   a controller coupled to the probe and configured to provide an output based on the signal from the measurement cell;   a first media access unit coupled to the controller and operably coupleable to a first process communication link, the first media access unit being configured to communicate in accordance with an all-digital process communication protocol;   a second media access unit coupled to the controller and operably coupleable to a second process communication link, the second media access unit being configured to communicate in accordance with a second process communication protocol that is different than the all-digital process communication protocol; and   wherein the first and second media access units are enabled simultaneously   
     
     
         2 . The in situ flue gas analyzer of  claim 1 , wherein the measurement cell includes an oxygen sensor. 
     
     
         3 . The in situ flue gas analyzer of  claim 1 , wherein the all-digital process communication protocol is in accordance with the FOUNDATION Fieldbus protocol. 
     
     
         4 . The in situ flue gas analyzer of  claim 1 , wherein a communication rate of the all-digital process communication protocol is faster than a communication rate of the second process communication protocol. 
     
     
         5 . The in situ flue gas analyzer of  claim 1 , wherein the second process communication protocol is a hybrid process communication protocol. 
     
     
         6 . The in situ flue gas analyzer of  claim 5 , wherein the hybrid process communication protocol superimposes a digital signal on an analog signal. 
     
     
         7 . A process combustion control system comprising:
 a combustion source operably coupled to a source of fuel and a source of air, the combustion source being configured to provide combustion gasses through a flue;   a combustion controller coupled to at least one of the source of fuel and source of air;   an in situ flue gas analyzer coupled to the combustion controller and disposed to sense a concentration of a gas of interest within the flue and convey process information related to the concentration to the combustion controller in accordance with an all-digital process communication protocol; and   wherein the in situ flue gas analyzer is communicatively coupled to a second device and communicates with the second device, in accordance with a second process communication protocol different than the all-digital process communication protocol, wherein communication with the combustion controller and the second device occurs substantially simultaneously.   
     
     
         8 . The process combustion control system of  claim 7 , wherein the gas of interest is oxygen. 
     
     
         9 . The process combustion control system of  claim 7 , wherein the in situ flue gas analyzer communicates with the combustion controller at a first communication rate, and communicates with the second device at a second rate that is less than the first rate. 
     
     
         10 . The process combustion control system of  claim 7 , wherein the second device is a user interface. 
     
     
         11 . The process combustion control system of  claim 10 , wherein the second process communication protocol is in accordance with the Highway Addressable Remote Transducer (HART) protocol. 
     
     
         12 . A method of operating an in situ flue gas analyzer, the method comprising:
 disposing a probe of the in situ flue gas analyzer within a flue;   measuring a concentration of a gas on interest using the probe;   communicating information regarding the measured concentration to a combustion controller in accordance with an all-digital process communication protocol; and   communicating with a second device in accordance with a second process communication protocol different than the all-digital process communication protocol.   
     
     
         13 . The method of  claim 12 , wherein the all-digital process communication protocol is the FOUNDATION Fieldbus protocol. 
     
     
         14 . The method of  claim 13 , wherein the second process communication protocol is the Highway Addressable Remote Transducer (HART) protocol. 
     
     
         15 . The method of  claim 12 , wherein communication with the combustion controller and the second device occurs substantially simultaneously. 
     
     
         16 . The method of  claim 15 , wherein communication with the combustion controller occurs at a first communication rate, and communication with the second device occurs at a second rate that is less than the first rate.