User's Manual

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Note d’étude / Technical document : URDx– OTL 5635.1– 007 / 70 230 Edition 03
Document Sagem Communications Reproduction et divulgation interdites
Sagem Communications document. Reproduction and disclosure prohibited
3.6 V24
The HiLo module features a V24 interface to communicate with the Host through AT commands or for easy
firmware upgrading purpose.
Pull-up resistors () must be connected to DCD, DTR, DSR and RI signals.
3.6.1 Complete V24 – connection HiLo - host
A V24 interface is provided on the main connector of the HiLo module with the following signals: RTS/CTS,
RXD/TXD, DSR, DTR, DCD, RI.
It is recommended to manage an external access to the V24 interface, in order to allow easy software upgrade.
RXD
TXD
RTS
CTS
DCD
RI
DTR
DSR
RXD
TXD
RTS
CTS
DCD
RI
DTR
DSR
DCE
(HiLo)
DTE
(Host)
GND GND
Figure 11: Complete V24 connection between HiLo and host
3.6.2 Complete V24 interface with PC
It supports speeds up to 115.2 Kbps and may be used in auto bauding mode.
To use the V24 interface, some adaptation components are necessary to convert the +2.8V signals from the HiLo to +/- 5V
signals compatible with a PC.
Note: Sagem communications recommends using this full interface.
To create your own data cable (for software download purpose…etc…) please refer to the following schematic
as an example: