The figure shows an application that uses a redundant pair of H1 with Integrated Power cards and intrinsic safety barrier protection for 12 devices on a long (0.5 km) trunk cable. If a failure occurs, the operator receives a hardware alert and the segments continue to operate as expected. If a short occurs when a device is installed or removed from the segment, only that device is affected; the rest of the segment continues to operate. A power supply is required if an H1 card is used. It is assumed that the application design follows the criteria specified in the DC power considerations for Intrinsically Safe applications topic.
