User's Manual

HiLo3G-850 User Manual
04 March 2011 - Page 19 / 36
However this configuration does not allow the signaling signals like:
RI signal used when programmed to indicate an incoming voice or data call or SMS incoming etc…
DCD signal used to signal the DATA connections
DSR signal used to signal the module UART interface is ON (need to pull high DSR with 470K ohm to external 3V,
shown as below)
DTR signal used to prevent HiLo3G-850 from entering into sleep mode or to switch between Data and AT commands or
to hang up a call or to wake up the module etc…
3.5.4 Partial V24 (RX-TX)Connection HiLo3G-850 -host
When using only RX/TX instead of the complete V24 link, the following schematic could be used.