Control/Digital Audio Interface (Dpl Bus); Control/Digital Audio Interface Signal Descriptions; Rs232 Data Interface; Rs232 Data Signal Descriptions - Iridium 9522B Product Information Manual

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9522B L-Band Transceiver Product Information Guide

4.2 Control/Digital Audio Interface (DPL bus)

4.2.1 Control/Digital Audio Interface Signal Descriptions

The control/digital audio interface enables peripherals such as handsets and SIM card readers to be
interfaced to the 9522B LBT. The interface utilizes an Iridium Proprietary communication bus not detailed
in this fact sheet. Details can be made available after appropriate Non-Disclosure and/or License
Agreements are executed.
The signal levels for the DPL bus (DPL_RX and DPL_TX signals) can be RS232 or logic level. The level
can be selected using the switch that is accessible when the SIM cover plate is removed as shown in
Figure 7 below. The switch should be moved to the right (when the unit is positioned with the connectors
facing the user) towards the RS232 lettering in copper on the PCB.
Logic-level RS-232
Figure 7: Location of DPL level switch

4.3 RS232 Data Interface

4.3.1 RS232 Data Signal Descriptions

The RS232 data interface is comprised of eight standard RS232 data, control, and status signals plus a
ground level signal reference. This interface allows a connected Data Terminal Equipment (DTE) to utilize
the 9522B LBT's modem functionality via AT command control. A 3-wire RS232 Data minimal interface
may also be implemented however the 9 wire interface offers better control and is the recommended
implementation.

4.3.2 Autobaud

Autobaud is enabled by default. Autobaud will occur on the following characters 'a', 'A', or CR (carriage
return). Autobaud will also occur on the escape sequence character, provided this is an odd number
character. Normally this is set to '+' in register S2. See the AT Command Reference for details.
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