US 11,880,181 B2
Digital safety locks in industrial process plants
Wallace A. Pratt, Jr., Pflugerville, TX (US); and Mark J. Nixon, Thorndale, TX (US)
Assigned to FIELDCOMM GROUP, INC., Austin, TX (US)
Filed by FIELDCOMM GROUP, INC., Austin, TX (US)
Filed on Sep. 9, 2021, as Appl. No. 17/470,799.
Prior Publication US 2023/0073577 A1, Mar. 9, 2023
Int. Cl. G05B 19/048 (2006.01)
CPC G05B 19/048 (2013.01) [G05B 2219/24024 (2013.01); G05B 2219/25428 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method at a field device of an industrial process plant, the method comprising:
receiving, by a field device in a locked mode and having a digital safety lock that is activated without using a physical lock, a request of a maintenance device to perform a maintenance activity associated with the field device,
the field device being functionally operable during run-time of a process control system to perform physical actions responsive to control signals to thereby control an industrial process, and
the locked mode indicative of the field device being functionally unresponsive to instructions issued by devices other than devices that provide indications of respective digital safety lock keys of one or more locking parties that activated one or more digital safety locks at the field device;
sending, by the field device to the maintenance device, an indication of a locking party included in the one or more locking parties;
responsive to the sent indication of the locking party, receiving, by the field device, an indication of a digital safety lock key; and
deactivating, by the field device, a digital safety lock activated by the locking party at field device when the received digital safety lock key corresponds to an actual digital safety lock key corresponding to the locking party.