Specifications

AC65/AC75 Hardware Interface Description
3.11 Serial Interface ASC1
s
AC65_AC75_HD_v01.002 Page 52 of 117 2006-10-30
Confidential / Released
3.11 Serial Interface ASC1
The ASC1 interface is available as a 4-wire unbalanced, asynchronous modem interface ASC1 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 2.9V (for high data bit or inactive state). For electrical charac-
teristics please refer to Table 26.
AC65/AC75 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:
• Port TXD @ application sends data to module’s TXD1 signal line
• Port RXD @ application receives data from the module’s RXD1 signal line
Figure 17: Serial interface ASC1
Features
• Includes only the data lines TXD1 and RXD1 plus RTS1 and CTS1 for hardware handshake.
• On ASC1 no RING line is available. The indication of URCs on the second interface depends on the settings
made with the AT^SCFG command. For details refer to [1].
• Configured for 8 data bits, no parity and 1 or 2 stop bits.
• ASC1 can be operated at fixed bit rates from 300 bps to 460,800 bps. Autobauding is not supported on ASC1.
• Supports RTS1/CTS1 hardware flow control and XON/XOFF software flow control.
Table 13: DCE-DTE wiring of ASC0
V.24 circuit DCE DTE
Pin function Signal direction Pin function Signal direction
103 TXD0 Input TXD Output
104 RXD0 Output RXD Input
105 RTS0 Input RTS Output
106 CTS0 Output CTS Input
108/2 DTR0 Input DTR Output
107 DSR0 Output DSR Input
109 DCD0 Output DCD Input
125 RING0 Output RING Input