Developer's Board Manual Rev A
Page 27 of 28
SEM/CX-02:0061/MAN
28 / RTS
Request To Send
The application will take control of this signal
when connected. The application must be
capable of handling a 1k ohm load.
30 / DFMS
Data From Module Station
The application and the development system
can use this signal at the same time.
37 / CTMS
Secondary data to module station.
This signal cannot be driven from the
application while connected to the
development system.
39 / CFMS
Secondary data from module station.
The application and the development system
can use this signal at the same time.
40 / RI
Ring Indicator. Default high. Low
pulse at 0.25Hz with 25% duty cycle
indicates an incoming call.
The application and the development system
can use this signal at the same time.
The power supplies (VCC_12V and VCC5V) are generated by the application. Do not connect the application
supplies to the development board. Only connect the Chassis signals of the development system (pins 5, 6, 8,
21, 22) to the application ground.
4.2 Serial
Control
Communication with the module is done through the main DB-9 RS-232 interface connector (J2). The J2
interface can be used as a line listener if the application connects to the 40-pin header pins 27 (DTMS) and pin 30
(DFMS). It is also possible to interject new commands to the module through J2 while the application is
connected to the 40-pin header. The only restriction is that data will be corrupted if it is sent from J2 at the same
time as the application sends data to the module.
Data that is sent to the module on DTMS will be echoed back out on DFMS, unless the echo is turned off through
an AT-command.
HW flow control (RTS, DTR) through J2 is not possible if the application is driving these pins through the 40-pin
header connector.
4.3 Audio
Interface
The audio signals are present in the 40-pin header on the following pins:
§
AGND – pin 9
§
ATMS – pin 10
§
AFMS – pin 7
Make sure that the S201 switch is set to BYPASS if the audio signal (ATMS) is input from the application at pin 10
of the header connector.
&
DTMS
DFMS
J2
Main RS-232
RxD
TxD
40-pin Header connector
DT
MS
DF
MS