US 12,316,469 B2
Secondary control for de-energizing safety field devices with digital protocols
Sergio Diaz, Round Rock, TX (US); and Gary Law, Round Rock, TX (US)
Assigned to Fisher-Rosemount Systems Inc., Round Rock, TX (US)
Filed by Fisher-Rosemount Systems Inc., Round Rock, TX (US)
Filed on Feb. 7, 2023, as Appl. No. 18/165,739.
Prior Publication US 2024/0267241 A1, Aug. 8, 2024
Int. Cl. G06F 15/173 (2006.01); H04L 12/10 (2006.01)
CPC H04L 12/10 (2013.01) 20 Claims
OG exemplary drawing
 
1. A two-wire routing device, the two-wire routing device comprising:
an upstream communication interface for communication with a controller;
a two-wire communication and power interface configured to convey communication and power to a field device over a two-wire link; and
a router electronic controller coupled to the upstream communication interface and the two-wire communication and power interface, the router electronic controller configured to:
receive, via the upstream communication interface, a safe state command from the controller, the safe state command including a field device identifier;
transmit, via the two-wire communication and power interface, the safe state command to a field device indicated by the field device identifier as a digital signal over the two-wire link; and
execute a secondary de-energization scheme for the field device, subsequent to transmitting the safe state command to the field device, to control a power switch to cut power over the two-wire link to the field device.