Rainbow Electronics DS2405 - Manual (Page 8)

DS2405
8 of 15
that same 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.