DS2405

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device is not found using an active-only search, CONTROL must be a logical 0 and the PIO pin is being

held low by some other device or perhaps a fault condition such as a PIO shorted to ground. A second

fault condition may be detected if Search ROM for a given device returns read-1 time slots (PIO=logical

1) but Active-Only Search ROM is successful (CONTROL=logical 1) and returns read-0 time slots for

the same device, indicating the possibility that PIO may be shorted to a positive voltage.