The present disclosure relates to a method for verifying the origin of electronic modules of a field device. Each manufacturer of an electronic module classified as trustworthy is assigned a key pair. Public keys classified as trustworthy are stored in a list in the field device. Each electronic module contains the public key of the manufacturer and a manufacturer signature. The manufacturer signature confirms the public key as trustworthy. When an electronic module is exchanged or added, the field device checks whether that module has a key pair and a manufacturer signature, whether the public key of the manufacturer of the electronic module is listed in the list with the public keys of the manufacturers classified as trustworthy, whether the manufacturer signature matches the manufacturer and the electronic module, and whether the electronic module is in possession of a correct private key.

An apparatus includes a housing, a touch sensor, a display, and a control module. The housing has a body defining a volume to accommodate a process control device and is adapted to withstand a threshold internal pressure greater than an external pressure. The housing further has a transparent portion having first and second surfaces. The touch sensor is disposed adjacent to the second surface of the transparent portion and senses an input received within a minimum distance from the first surface of the transparent portion. The display is disposed adjacent to the touch sensor and displays at least one adjustable variable corresponding to the process control device.

An apparatus includes a housing, a touch sensor, a display, and a control module. The housing has a body defining a volume to accommodate a process control device and is adapted to withstand a threshold internal pressure greater than an external pressure. The housing further has a transparent portion having first and second surfaces. The touch sensor is disposed adjacent to the second surface of the transparent portion and senses an input received within a minimum distance from the first surface of the transparent portion. The display is disposed adjacent to the touch sensor and displays at least one adjustable variable corresponding to the process control device.