Field wiring connectors are removed from the existing IPC-620 I/O cards and re-installed on the MIBRIDGE® adapter cards. The adapter card accepts the field wiring connectors directly meaning there is no need to modify the field wiring. This saves time and more importantly eliminates the chance of wiring errors. A cable interfaces each adapter card to the new control system. Adapter cards are specific to the number of I/O channels on the original IPC-620 I/O card, not the type of I/O. For example, all 16 channel IPC-620 I/O cards, regardless of whether they are input or output cards, are replaced by a common 16 channel adapter card. The cable to the new control system can be generic (provided with flying leads for connection to the new I/O card) or specific to the new I/O card (provided with a connector specific to that I/O card).