A mobile device for determining cable connections between field devices and I/O modules in a process control system, wherein the mobile device includes a cable interface arranged to be connected to a cable, a user interface configured to receive a user selection of a field device identifier identifying a field device in the process control system, and a processor configured to send an I/O module identification query via the cable interface to an I/O module connected to the cable interface by means of a cable, receive, via the cable interface, I/O module identification data from the I/O module in response to the I/O module identification query, and to associate a user-selected field device identifier with the I/O module identification data received by the processor. An engineering tool device, a system and corresponding methods are also disclosed herein.
