User's Guide

The Hardware View SB300 Series
Page 92 Proprietary and Confidential 2110059 Rev 1.0
PC Serial Port
This connection is for a PC host device running a terminal emulation program. Communication to
and from this port is delivered via the Serial Breakout Box, to and from the modem.
Debug Port
The second 9-pin D connector is for factory level testing only.
10.4.2. Host (DTE) Connection for SB302
An alternative to the 9-pin RS-232 serial connector (PC Serial Port) is provided for connecting a
host (DTE) device to a SB302 via the 2x8-pin block at J9 (SB301/302 To Host). This connector
allows you to insert the MIB between the host and the modem for testing and monitoring
communications.
Although there is not currently an equivalent 30-pin ZIF host connector for the SB300 and SB320,
the pins of this connector are also delivered to the SB300 / SB320 modem connectors.
Serial Signals
The MIB converts the serial communication signals to RS-232 level, presents them at the Serial
Breakout Box and then converts them back to HCMOS level before passing them to the DTE/DCE
ends.
NOTE: In order for this signal conversion to work, the host device MUST supply +5V on pins 1
and 2. It is this power which enables the conversion logic on the MIB for the host side.
Input Signals
The modem’s three \STATUS_OUT signals are passed directly between the modem and the host.
They can also be monitored by the three LEDs (SO1, SO2, SO3)
Output Signals
The host Shutdown signal is passed to the modem via an enabling jumper (HOSTSHDN) on the
main jumper block. With the jumper removed, the shutdown signal is blocked from reaching the
modem.
Power from the host can be used to power the modem by setting jumper J21 (Power Select) to pins
2 –3 (+5V Host). With the jumper in the original position (pins 1 – 2) the modem is powered from
the MIB. See Section 10.3.2 for details.
10.4.3. Protocol Analyzer Connection
Two 25-pin D connectors are available to connect a protocol analyzer in the serial signal path.
The female connector is on the PC side of the Serial Breakout Box; the male connector is on the
modem side.
To monitor the communication signals between the host and modem, simply connect the analyzer
to the MIB.
10.4.4. SB300 / SB320 Modem Connection
Both the SB300 and SB320 use a 30-pin ZIF connector. The connector uses the Flat Flex Cable
ribbon (Sierra Wireless part number 2000068) provided with the OEM Developer’s Toolkit.
The connection provides all defined pinouts.
Use care when attaching the ribbon to the connector. There is a cover clamp that hinges up to
open the connector. Slide the ribbon into the connector with the insulated (coloured) side of the
ribbon facing up. Close the connector clamp by pressing down at the ends rather than the centre
of clamp. The modem has an identical clamp connector.