User manual

1-Wire Application Guide v1.04 Page 28 of 41
Figure 20 1WIO Input Wiring
Up to 40 1WIO’s can be connected to TEMP08 in this manner. Mixing input and
LED versions of 1WIO on TEMP08 can be tricky since connecting at least 1
1WIO input device will require the use of the EIN ON command, which will cause
issues with 1WIO LED devices in some early versions of TEMP08 software. The
top 4 LED’s on a 1WIO LED device would blink out when EIN ON is set on
TEMP08. If this occurs, consider upgrading your TEMP08 software.
Another way to determine the status of a contact is to use the trick that Dallas
Semiconductor originally used for the 1-Wire Wind Direction Sensor; place the
contact switch between the DQ line and any sensor’s DQ input per Figure 21.
Whenever the contact, SW1, is open, TEMP08 will report the corresponding
sensor U1 as “missing”. When the contact closes, TEMP08 will report the sensor
as “present”.