A system for detecting anomalies in electrical wiring in a truck trailer. The system measures and compares current drawn from the truck tractor with the current drawn by a circuit at a particular trailer component or other location in the trailer wiring. If the two current measurements differ in excess of a predetermined threshold, the system can report a wiring anomaly. The location of the anomaly can then be determined by performing the operation for different trailer components thus testing multiple different branches of the trailer power distribution circuit, and using the results of these tests to determine that an anomaly is present, and possibly the location of the issue. The system may then send a notification to a remote computing device, to the truck tractor, or any combination thereof.

An indexing system includes an indexing component; a redundant optical path; and a fiber tap arrangement. Multiple indexing components can be daisy-chained together in the indexing system. The redundant optical path is created between any forward port and any rearward port in the network. Multiple redundant optical paths can be created within the network. One or more tap arrangements can be disposed along each redundant optical path. Accordingly, feed signals in a bidirectional indexing environment can be supplied to each drop line along the redundant optical path from either direction without recabling.

An indexing system includes an indexing component; a redundant optical path; and a fiber tap arrangement. Multiple indexing components can be daisy-chained together in the indexing system. The redundant optical path is created between any forward port and any rearward port in the network. Multiple redundant optical paths can be created within the network. One or more tap arrangements can be disposed along each redundant optical path. Accordingly, feed signals in a bidirectional indexing environment can be supplied to each drop line along the redundant optical path from either direction without recabling.

An optical communication device according to an embodiment is provided with: a communication circuit for transmitting and receiving a signal using a first communication optical fiber connected to a first port; a tester circuit for transmitting and receiving a test signal using a loop-back optical fiber connected to a second port; a determining unit which, when the amount of optical reception of the test signal is lower than a threshold value, determines that the loop-back optical fiber is degraded; and a notifying unit for notifying a determination result from the determining unit.

Disclosed herein are devices, systems, and methods for selectively configuring an optical coupling network between a modem and optical head to calibrate the timing delay of the entire receive path and entire transmit path. The device includes a modem with a transmit and receive path and an optical head with an optical transmit path, an optical receive path, and a calibration path. The device includes an optical coupling network for selectively routing signals (i) through a first loopback path comprising the transmit path and the receive path; (ii) through a second loopback path comprising the transmit path, the optical transmit path, the optical receive path, and the receive path; (iii) through a third loopback path comprising the transmit path, twice the calibration path, and the receive path; and (iv) through a fourth loopback path comprising the transmit path, the calibration path, the optical receive path, and the receive path.

Disclosed herein are devices, systems, and methods for selectively configuring an optical coupling network between a modem and optical head to calibrate the timing delay of the entire receive path and entire transmit path. The device includes a modem with a transmit and receive path and an optical head with an optical transmit path, an optical receive path, and a calibration path. The device includes an optical coupling network for selectively routing signals (i) through a first loopback path comprising the transmit path and the receive path; (ii) through a second loopback path comprising the transmit path, the optical transmit path, the optical receive path, and the receive path; (iii) through a third loopback path comprising the transmit path, twice the calibration path, and the receive path; and (iv) through a fourth loopback path comprising the transmit path, the calibration path, the optical receive path, and the receive path.