Continuously powered field device

A method of providing continuous power to a field device in a process control system, the method comprising:

• providing a field device housing;
• providing a network interface communicatively coupled between a host and a process function block within the field device, the network interface is configured to perform at least one of:
• transmit signals to the host or receive signals from the host;
• providing a module disposed within, or externally connected to, the field device housing, the module being configured to perform one or more of (i) a control function, (ii) a monitoring function, or (iii) a physical function, within the process control system;
• providing a primary power port, wherein the primary power port includes a first connector configured to electrically and mechanically couple to a first mating connector of a primary power source comprising a first set of one or more batteries, and wherein the primary power port and the primary power source are both disposed within the field device housing when the first connector and the first mating connector are electrically and mechanically coupled together and the field device housing is in the closed position;
• providing a backup power port connected to the field device housing, wherein the backup power port includes either (i) a second connector configured to electrically and mechanically couple to a backup power source comprising a second set of one or more batteries via a second connector included on the backup power source, or (ii) a plurality of protruding structures each configured to electrically and mechanically couple to the backup power source via a respective one of a plurality of clips connected to wire leads of the backup power source, wherein the backup power source is a module that is external of the field device;
• integrating a battery within the field device;
• providing a first power terminal, a second power terminal, and a third power terminal, wherein
• the first power terminal is coupled to the primary power port,
• the second terminal is coupled to the backup power port, and
• the third power terminal is configured to deliver power applied to the third power terminal to at least a portion of the field device;
• automatically coupling the first power terminal to the third power terminal during a first state of operation;
• and
• automatically coupling the second power terminal to the third power terminal during a second state of operation, wherein the network interface and the module are continuously powered via the third power terminal while at least one of the primary power source or the backup power source is capable of providing power to the field device, and wherein at least a powered portion of the field device is powered by the battery that is integrated within the field device, when the battery that is integrated within the field device is capable of providing power, and is not ever powered by the primary power source.

An intrinsically safe (IS), continuously powered, field device for use in a hazardous environment within a process control system, the field device comprising:

• a field device housing;
• a network interface disposed within, or externally connected to, the field device housing and communicatively coupled between a host and a process function block, the network interface is configured to perform at least one of:
• transmit signals to the host or receive signals from the host;
• a module disposed within, or externally connected to, the field device housing, the module being configured to perform one or more of (i) a control function within the process control system, (ii) a monitoring function within the process control system, or (iii) a physical function within the process control system;
• a primary power port, wherein the primary power port includes a first connector configured to electrically and mechanically couple to a first mating connector of a primary power source comprising a first set of one or more batteries, and wherein the primary power port and the primary power source are both disposed within the field device housing when the first connector and the first mating connector are electrically and mechanically coupled together and the field device housing is in the closed position;
• a backup power port connected to the field device housing, wherein the backup power port includes either (i) a second connector configured to electrically and mechanically couple to a backup power source comprising a second set of one or more batteries via a second mating connector included on the backup power source, or (ii) a plurality of protruding structures each configured to electrically and mechanically couple to the backup power source via a respective one of a plurality of clips connected to wire leads of the backup power source, wherein the backup power source is a module that is external of the field device;
• a battery integrated within the field device;
• and
• a power source switching module comprising a first power terminal, a second power terminal, and a third power terminal, wherein
• the first power terminal is coupled to the primary power port,
• the second power terminal is coupled to the backup power port,
• the third power terminal is configured to deliver power applied to the third power terminal to at least a portion of the field device,
• the power source switching module in a first state of operation couples the first power terminal to the third power terminal, and
• the power source switching module in a second state of operation couples the second power terminal to the third power terminal, wherein the network interface and the module are continuously powered via the third power terminal while at least one of the primary power source or the backup power source is capable of providing power to the field device, and wherein at least a powered portion of the field device is powered by the battery that is integrated within the field device, when the battery that is integrated within the field device is capable of providing power, and is not ever powered by the primary power source.