Hayes Microcomputer Products ASLH306 - Manual (Page 6)

ASL Holdings Limited 19/09/2005 6
Draft Copy Version 2c
The 25 way D-type connector is wired as follows:
Pin number, name and mnemonic:
2
Transmit Data TxD
3 Receive Data RxD
4 Request to Send RTS
5 Clear to Send CTS
6 Data Set Ready DSR
7 Signal Ground/Supply Ground SG
8 Data Carrier Detect DCD
9 Power In PI
15 Power In PI
20 Data Terminal Ready DTR
22 Ring Indicator RI
Supplying power to the modem
The Delta Plus MOBILE II GSM/GPRS modem is powered via the RS232
interface connector. Pins 9 and/or 15 require a +7 to +24 Volts DC supply
(issue F. board) Earlier issues of the board require +7 to +15Volts. The
modem consumes 0.3 Watts. (See appendix). The supply to the modem is
floated across internal SuperCaps. These devices hold a considerable charge
and will allow the modem LED’s to continue to function for several minutes
after the removal of the power supply. This enables the modem to be used in
environments where the power supply is either intermittent and/or inadequate
(within reason) for a conventional modem product.
Battery powered version.
The GSM/GPRS modem is also available as a battery powered device. The
battery employed in the modem is a Lithium Ion Polymer
type and is subject
to a minimum duty cycle of 1000 operations.
The battery is fitted in addition to the “Super Caps” that are present in
the standard modem and will power the modem for approximately two
minutes after the external supply has been removed. This is regardless of
whether or not the modem is on line. When the modem shuts down it will
issue a “Goodbye” message to the interface.
Additionally the modem can be switched off using an AT command.
The AT+K command will shutdown the entire modem (not just the Sony
Ericsson module as is the case with other ASLH 306 products) within 15
seconds. If the power supply to the modem is not removed within 30 seconds