User Guide

Iridium Communications Inc. Information Contained in this Guide
9602 SBD Transceiver Product Developers Guide is Subject to Change Without Notice
Revision 1.2 (DRAFT 2)
Iridium Communications Inc. Distribution of Guide Restricted
Proprietary & Confidential Information 25 to Product Developers Only
Table 10 – Serial Interface Signals
Signal
Description
RX Active high data output [The DTE receives the data from the 9602/9602N]
TX Active high data input [Data is transmitted from the DTE to the 9602/9602N]
G
ND
0V
RTS
Active low flow contro
l input
CTS
Active low flow control output
RTS and CTS are used together to implement hardware flow control when enabled with
AT&K3
DTR
Active low handshaking input
AT&Dn controls how the 9602/9602N uses DTR:
• If set to AT&D0, DTR is always ignored.
• Otherwise DTR set to OFF places the data port into UART test mode after 10
seconds, or immediately on boot-up. A subsequent transition of DTR to ON returns
the data port to DCE mode and resets it to its power-on state.
• The UART test mode is provided for factory testing of the data port UART. An FA
should never activate test mode; if it does, the 9602/9602N will stop responding to
AT commands until the data port is returned to DCE mode.
DSR
Active low handshaking output
The 9602/9602N drives DSR ON when the data port is in DCE mode, and OFF when the
data port is in test mode.
The DTE may use this signal as an indication that the 9602/9602N is powered up and
ready to receive AT commands.
RI
Active low ring indicator output
The 9602/9602N drives RI ON when it receives a Automatic Notification from the
network that a Mobile Terminated SBD Message is queued at the Gateway, and drives
RI OFF after 5 seconds or when the DTE initiates an SBD session, whichever occurs
first.
DCD
Active low handshaking output
DCD is driven OFF at all times.
Note that the Ring Indicator (RI) pin is used by the 9602/9602N SBD Transceiver to indicate that a Mobile
Terminated SBD (MT-SBD) message is queued at the Gateway. The Field Application can monitor this
pin and use appropriate AT Commands to command the Transceiver to retrieve the MT-SBD message.
The serial interface may be operated with a 3-wire connection, where only transmit, receive and ground
signals are used. However the 9 wire interface offers better control and is the recommended
implementation. Iridium is only able to provide limited 3-wire interface support. Due to the small code
space and limited processing resources of the 9602/9602N the flow control is limited.
When operating with a 3-wire connection, the following rules apply:
• AT&Dn must be set to AT&D0 to ignore the DTR input
• AT&Kn must be set to AT&K0 to disable RTS/CTS flow control
• The other output signals may be connected, and operate as follows:
• CTS driven ON (low)
• DSR operates as normal
• RI operates as normal
• DCD driven ON (low)