Most DDU fiber errors can be cleared by sending a hard reset followed by a resync (using, for instance, the LTC control interface). Resetting the DDU in this way does not guarantee that the underlying cause of the fiber error is fixed, so the error may show up again immediately (at the next L1A) or in the future, when the conditions for the error are again met. Under normal operating conditions, one of these errors occurring on a DDU should automatically generate an FMM error for that DDU, telling the global trigger system to send an appropriate reset to the detector. During commissioning runs, however, a threshold can be set on a per-endcap basis that prevents the DDU from send its FMM error unless a certain number of DDU fiber errors are detected on that particular endcap.