Section A.2 - Application Notes.Design Examples
Version 1.3 - 2009-12
43
A.2.3.2 RED/Mode
Signal
The RED logic LED signal is not multiplexed with any other functionality. See Figure 19 for a
3.3V design.
In a 5V system the high state output (2.8V) from the module is not enough to turn off the LED
so a 74HCT08 buffer can be used to raise the high level to 5V (see Figure 20).
The 74HCT08 gate is available in a single gate package (74AHCT1G08).
Figure 19: A red LED in a 3.3V host system. The
status of the signal can also be used as input to a
host controller.
Figure 20: A red LED in a 5V host system. The
status of the signal can also be used as input
to a host controller.
The RED signal pin is also used to select Logic Level mode (instead of RS232) for connectBlue
product with internal RS232 driver e.g. cB-OEMSPA312. The mode functionality is not applicable
on cB-OZS311 because there is no internal RS232 driver available. To be compatible with these
products check this signal in their Electrical and Mechanical datasheet.
