Power Issues:
The LINK provides an Auxiliary I/O line on the RJ connector. The LinkHub-E provides
sw5V on the same pin.
Scanning:
It is often useful to scan the 1-Wire bus and report the
arrival
of a new 1-Wire device or
the
departure
of a device from the bus. The LinkHub-E includes a bus scanning function
for this purpose. When turned ON using the ‘$’ character, the scanning system
continually performs First and Next device discovery operations and builds a table of up
to eight (8) device serial numbers. As a new device appears on the 1-Wire bus, and after
the same device serial number (with correct CRC8 and a non-zero family code) has been
observed on two subsequent full discovery passes, an Arrival is reported as a string with a
“!” (exclamation-point) character, a comma, and the arriving device serial number.
When a device has been present on the bus and then is not found in ten (10) successive
complete discovery cycles, it is reported as a Departure with a “?” (question mark)
followed by a comma and the serial number of the device that departed from the bus.
(This de-bounces the departure.)
While scanning is active the current contents of the table can be reported with the “*”
command.
Scanning is terminated by a Reset, First, Next or any number of other operations.
The scanning system will not work properly if more than 8 iButton or 1-Wire devices
are present on the bus. This is due to the limited memory available in the LinkHub-E.
Questions about the LinkHub-E should be directed to
.
Copyright © 2008 by iButtonLink LLC
iButton and 1-Wire are trademarks of Dallas Semiconductor Corp, Dallas, Texas, USA.
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