d15 Modem Integration and Application Developers Guide version draft 0.53 Page 36 of 181
25
7
28
26
14
27
21
13
TXD
DTR
RTS
RXD
DCD
CTS
DSR
RI
TXD
DTR
RTS
RXD
DCD
CTS
DSR
RI
D15
processor
TXD
DTR
RTS
RXD
DCD
CTS
DSR
RI
D15
D15 is a DCE device
User connector28 pin DIN
Host is a DCE device
Figure 19 - DCE connection to d15 (user connector 28 pin DIN)
There are two modes to use the Data port:
−
SoftGsm mode. This mode is for computer application in which an application SW
“SoftGSM” is use. This allowed the D15 to work with V42.bis (data compression), transfer
fax and SMS. In this mode Transparent data is available. In this mode Voice calls via AT
commands are not available.
−
RS232 full flow control. This is the default setting for the D15. In this mode we can transfer
data and SMS using a full flow control (HW flow control), Xon/Xoff or non flow control.
There is no FAX capability in this mode.
In this mode Non transparent data is available and voice calls using AT commands are
available.
3.3.2 Select the data mode:
The D15 can support two different modes of operation:
SoftGsm - For PC applications.
RS232 full flow control - General applications.
The RS232 is the default mode and no action is needed to switch to this mode.
The SoftGsm require hardware connection to two lines.
Down link
pin should be connected via 22KOhm to ground.
DSC_EN
pin should be connected via 22KOhm to ground.
3.3.3 DTR line.
The DTR line must to be active (0V) in order to recognize the DTE by the D15.
If the DTR is not used by the application connect this line to ground (DTR Active).