User Guide

LE866 Hardware Design Guide
1VV0301355 Rev. 5 Page 47 of 91 2019-04-05
8
C105/RTS
B1
Request to Send
Input to the LE866 that controls the
Hardware flow control
9
C125/RING
B3
Ring Indicator
Output from the LE866 that indicates
the incoming call condition
NOTE:
According to V.24, some signal names are referred to the application
side, therefore on the LE866 side these signal are on the opposite
direction:
TXD on the application side will be connected to the receive line
(here named C103/TXD)
RXD on the application side will be connected to the transmit line
(here named C104/RXD)
For a minimum implementation, only the TXD, RXD lines can be
connected, the other lines can be left open provided a software flow
control is implemented.
In order to avoid a back powering effect it is recommended to avoid
having any HIGH logic level signal applied to the digital pins of the
LE866 when the module is powered off or during a reboot transition.