Sierra Wireless MC5720, Hardware Integration Manual, Page: 19 / 30

4
4: Host/Module Communication
Interface
This chapter provides information about the Host ‐ Module
communication interface (USB interface) and lists of extended
AT commands that may be useful for hardware integration
testing.
Note: On any given interface (USB, USIM/RUIM, etc.), leave unused
inputs and outputs as no-connects.
LED output
The module drives the LED output according to the PCI ‐
Express MiniCard specification (summarized in Table 4 ‐ 1,
Module is transmitting LED is flashing intermittently,
or receiving.
proportional to activity on the
interface.
• 50% duty cycle
• 3 Hz minimum blink rate
• 20 Hz maximum blink rate
Rev 0.92 Nov.05 17
below).
Table 4-1: LED States
State Indicates Characteristics
OFF Module is not
powered. Light is turned off.
ON
Module is powered
and connected, but
not transmitting or
receiving. Light is turned on.
Slow Blink Module is powered
and searching for a
connection. LED is flashing at a steady,
slow rate.
• 250 ms ± 25% ON period
• 0.2 Hz ± 25% blink rate
Intermittent
Blink