Gemalto M2M GmbH AHS3-US User Manual
AHS3-US Hardware Interface Overview
3.4 Serial Interface ASC0
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AHS3-US_HIO_v02.540
Page 22 of 39
2012-09-05
Confidential / Preliminary
3.4
Serial Interface ASC0
AHS3-US offers an 8-wire unbalanced, asynchronous modem interface ASC0 conforming to
ITU-T V.24 protocol DCE signalling. The electrical characteristics do not comply with ITU-T
V.28. The significant levels are 0V (for low data bit or active state) and 1.8V (for high data bit
or inactive state).
ITU-T V.24 protocol DCE signalling. The electrical characteristics do not comply with ITU-T
V.28. The significant levels are 0V (for low data bit or active state) and 1.8V (for high data bit
or inactive state).
AHS3-US is designed for use as a DCE. Based on the conventions for DCE-DTE connections
it communicates with the customer application (DTE) using the following signals:
•
it communicates with the customer application (DTE) using the following signals:
•
Port TXD @ application sends data to the module’s TXD0 signal line
•
Port RXD @ application receives data from the module’s RXD0 signal line
Figure 4: Serial interface ASC0
Features:
•
•
Includes the data lines TXD0 and RXD0, the status lines RTS0 and CTS0 and, in addition,
the modem control lines DTR0, DSR0, DCD0 and RING0.
the modem control lines DTR0, DSR0, DCD0 and RING0.
•
ASC0 is designed for controlling GSM/UMTS voice calls, transferring data and for control-
ling the module with AT commands.
ling the module with AT commands.
•
Full multiplexing capability allows the interface to be partitioned into virtual channels.
•
The RING0 signal serves to indicate incoming calls and other types of URCs (Unsolicited
Result Code). It can also be used to send pulses to the host application, for example to
wake up the application from power saving state. See
Result Code). It can also be used to send pulses to the host application, for example to
wake up the application from power saving state. See
for details on how to configure the
RING0 line by AT^SCFG.
•
Configured for 8 data bits, no parity and 1 stop bit.
•
ASC0 can be operated at fixed bit rates from 9600bps up to 921600bps.
•
Autobauding is supported.
•
Autobauding is not compatible with multiplex mode.
•
Supports RTS0/CTS0 hardware flow control.
•
Wake up from SLEEP mode by RTS0 activation (high to low transition).
Note. If the ASC0 serial interface is the application’s only interface, it is suggested to connect
test points on the USB signal lines as a potential tracing possibility.
test points on the USB signal lines as a potential tracing possibility.