公开(公告)号：CA2169722A1

公开(公告)日：1995-03-23

申请号：CA2169722

申请日：1994-08-15

Applicant: ROSEMOUNT INC

Inventor： VOEGELE KEVIN D ,  LANCTOT JANE B ,  WESTFIELD BRIAN L

IPC: G01R27/14 ,  G01R31/28

Abstract: An improved error detection for microprocessor-based transmitters in two-wire process control loops operating in the process control industry. In particular, techniques are shown which are useful in solving malfunctions or failures of microprocessor-based transmitters. When the transmitter is energized, the impedance of the process loop cabling is resolved and stored, displayed or transmitted as desired. The loop impedance is used to calculate potential of a power supply used to power the control loop. This information is used in testing the two-wire loop.

公开(公告)号：CA2119438A1

公开(公告)日：1993-04-01

申请号：CA2119438

申请日：1992-08-20

Applicant: ROSEMOUNT INC

Inventor： ANDERSON STEPHEN D ,  FRICK ROGER L ,  MONZO GLEN E ,  WESTFIELD BRIAN L

IPC: G08C19/02 ,  G08C19/00

Abstract: A three wire transmitter bidirectionally communicates AC signals to and from a first external device and sends DC signals to a second external device. The transmitter includes a sensor circuit and a communication circuit, both energized from power and common terminals of the transmitter. The communication circuit receives a sensor output indicating a sensed process variable and provide DC and AC signals to a signal terminal which connects to both external devices, and also receives AC signals from the first external device. The DC signal is representative of the sensed process variable and the AC signal is digitally representative of the sensed process variable and of transmitter data selected by the received AC signal.

公开(公告)号：EP0606260A4

公开(公告)日：1994-08-10

申请号：EP92919210

申请日：1992-08-20

Applicant: ROSEMOUNT INC

Inventor： ANDERSON STEPHEN D ,  FRICK ROGER L ,  MONZO GLEN E ,  WESTFIELD BRIAN L

IPC: G08C19/02 ,  G08C19/00

CPC classification number: G08C19/02