公开(公告)号：EP0870288A1

公开(公告)日：1998-10-14

申请号：EP97941662.0

申请日：1997-09-17

Applicant: ROSEMOUNT INC.

Inventor： ANDERSON, Stephen, D. ,  JOHNSON, Theodore, L. ,  JUNK, Brian, S. ,  ORMAN, Michael, A. ,  SCHNAARE, Theodore, H. ,  TETZLAFF, David, E.

IPC: G08C19 ,  H02M7

CPC classification number: H02M7/219 ,  G08C19/02 ,  Y10T307/858 ,  Y10T307/865

Abstract: A field instrument (10) includes an input circuit (26) having a transistor bridge rectifier (Q1, Q2, Q3, Q4) which is couplable to a power supply. The transistor bridge rectifier (Q1, Q2, Q3, Q4) is configured to provide power from the power supply to a remainder of the field instrument (10).

公开(公告)号：EP0864122A1

公开(公告)日：1998-09-16

申请号：EP97942672.0

申请日：1997-09-23

Applicant: ROSEMOUNT INC.

Inventor： TETZLAFF, David, E. ,  WARRIOR, Jogesh ,  MAALOUF, Gabriel, A.

IPC: G05B15 ,  G05B19

CPC classification number: G05B19/0421 ,  G05B15/02 ,  G05B19/4185 ,  G05B2219/25145 ,  Y02P90/18

Abstract: The present invention includes a process control instrument (100) having an improved data bus protocol for facilitating communications between master and slave nodes. The process control instrument (100) includes a microprocessor (200) operating in accordance with the SPI data bus protocol, first and second peripheral devices (204, 206), and a data bus (220) coupled to the microprocessor and the first and second peripheral devices. The improved data bus protocol used in the process control instruments of the present invention provides numerous advantages such as reduced printed circuit board space requirements and greater interchangeability of peripheral and master node components.

公开(公告)号：EP0783800A1

公开(公告)日：1997-07-16

申请号：EP95931804.0

申请日：1995-09-11

Applicant: ROSEMOUNT INC.

Inventor： GOETZINGER, Charles, E. ,  TETZLAFF, David, E.

IPC: H03M1

CPC classification number: H03M1/1009 ,  H03M1/14 ,  H03M1/52 ,  H03M1/60

Abstract: A calibrating system calibrates an analog-to-digital converter which has an integrator (20) and first and second reference current sources (IL, IS). A quantity of charge is accumulated in the integrator (20). The quantity of charge is removed from the integrator (20) by applying the first and second reference currents (IL, IS) to the integrator (20) for first and second time periods until the accumulated charge reaches a threshold level. The quantity of charge is reaccumulated in the integrator (20) and again removed by applying the first and second reference currents (IL, IS) for third and fourth time periods wherein the first and second time periods are different from the third and fourth time periods. The relative magnitude of the first and second reference currents (IL, IS) is determined based on the first, second, third and fourth time periods.