Adjustable bandwidth filter for process variable transmitter
First Claim
Patent Images
1. A process variable transmitter, comprising:
- a sensor circuit adapted to sense a process variable and provide at least one sensor output;
a filter coupled to the sensor circuit and having a bandwidth that automatically decreases as sensor noise increases at the at least one sensor output to damp noise, and automatically increases as sensor noise decreases at the at least one sensor output; and
a communication circuit coupled to the filter and providing a transmitter output representing the process variable and having damping automatically adjusted for sensor noise.
1 Assignment
0 Petitions
Accused Products
Abstract
A process variable transmitter providing a transmitter output representing a process variable sensed by a sensor. The transmitter has a filter with a bandwidth which is automatically adjusted based on noise detected in a sensor output. When the transmitter senses higher sensor noise levels, it automatically decreases the bandwidth to damp noise in the transmitter output. When the transmitter senses lower sensor noise levels, it automatically increases the bandwidth to provide faster response to changes in the process variable.
-
Citations
30 Claims
-
1. A process variable transmitter, comprising:
-
a sensor circuit adapted to sense a process variable and provide at least one sensor output;
a filter coupled to the sensor circuit and having a bandwidth that automatically decreases as sensor noise increases at the at least one sensor output to damp noise, and automatically increases as sensor noise decreases at the at least one sensor output; and
a communication circuit coupled to the filter and providing a transmitter output representing the process variable and having damping automatically adjusted for sensor noise. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A process variable transmitter couplable to a process plant, comprising:
-
filtering circuitry adapted to receive a first signal from the process plant and to provide a filtered signal which is bandwidth limited by the filtering circuitry and which represents the magnitude of a process variable;
communication circuitry adapted to receive the filtered signal and to transmit a transmitter output signal representing the process variable to a communication link; and
adjustment circuitry adapted to receive a second signal that includes noise from the process plant and to automatically adjust the bandwidth of the filtering circuitry to reduce noise in the transmitter output signal as a function of the noise included in the second signal. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
-
-
24. A method for filtering a process variable sensor signal, comprising:
-
receiving a process variable sensor signal from a sensor;
sensing noise in the process variable sensor signal;
filtering the process variable sensor signal with an adjustable bandwidth filter;
generating a damped process variable transmitter output as a function of the filtered process variable sensor signal; and
adjusting damping of noise in the damped process variable transmitter output by automatically adjusting the adjustable bandwidth filter as a function of the sensed noise in the process variable sensor signal. - View Dependent Claims (25)
-
-
26. A computer-readable medium having stored thereon a plurality of sequences of instructions, the plurality of sequences of instructions including sequences of instructions which, when executed by a processor, cause the processor to perform the sequence:
-
acquiring a process variable sensor signal from a sensor;
filtering the process variable sensor signal with an adjustable bandwidth filter;
providing a damped process variable transmitter output as a function of the filtered process variable sensor signal;
sensing noise in the process variable sensor signal; and
adjusting damping of noise in the damped process variable transmitter output by automatically adjusting the adjustable bandwidth filter as a function of the sensed noise in the process variable sensor signal.
-
-
27. A process variable transmitter, comprising:
-
a sensor circuit sensing a process variable and providing at least one sensor output;
a filter coupled to the sensor circuit and having an adjustable bandwidth;
a communication circuit coupled to the filter and providing a damped transmitter output representing the process variable; and
means for sensing sensor noise and for automatically adjusting the adjustable bandwidth to increase the damping as sensor noise increases at the at least one sensor output and to decrease the damping as sensor noise decreases at the at least one sensor output.
-
-
28. A process variable transmitter, comprising:
-
a sensor circuit adapted to sense a process variable;
a filter control circuit coupled to the sensor circuit and having a filter control output indicating a bandwidth that automatically decreases at higher sensor noise to damp noise, and automatically increases at lower sensor noise; and
a communication circuit coupled to the filter control circuit and the sensor circuit and adapted to couple to a digital control system, the communication circuit providing a first transmitter output representing the process variable and providing a second transmitter output representing the filter control output.
-
-
29. A digital control system adapted for coupling to process variable transmitters, comprising:
-
a first transmitter input adapted to couple to a first transmitter providing a first process variable;
a second transmitter input adapted to couple to a second transmitter providing a second process variable known to correlate with noise in the first process variable; and
a filtering circuit receiving and filtering the first transmitter input with an adjustable bandwidth set by the second process variable such that bandwidth decreases when noise in the first process variable increases. - View Dependent Claims (30)
-
Specification