Gemalto M2M GmbH PLS8-USR3 Manuel D’Utilisation

®

3.4 Serial Interface ASC0



PLS8-USR3_HIO_v03.012

2015-10-13

Confidential / Released

Page 23 of 41

PLS8-US R3 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). 

PLS8-US R3 is designed for use as a DCE. Based on the conventions for DCE-DTE connec-
tions 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 RING0 signal serves to indicate incoming calls and other types of URCs (Unsolicited
Result Code). It can also be configured to send pulses to the host application, for example
to remotely 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 115200bps up to 921600bps.

•

Supports RTS0/CTS0 hardware flow control.

•

Wake up from SLEEP mode by RTS0 activation.

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.