Enfora Enabler II-G Assisted GPS Modem Integration Guide
6.6.2. Ring Indicate
The Enabler II-G A-GPS module is capable of using the Ring line to discern the type of
incoming call. The indicator can be monitored via a hardware line available on the 60-pin I/O
signal connector. The Ring Indicator pin is #49.
The function of the Ring line depends on the type of the call received.
When the module is receiving a voice call, the Ring line goes low for 1 second and high for
another 2 seconds. Every 3 seconds the ring string is generated and sent over the Receive
(Data Out) (Rx) line. If there is a call in progress and call waiting is activated for a connected
handset or hands free device, the Ring pin switches to ground in order to generate acoustic
signals that indicate the waiting call.
When a Fax or data call is received, Ring goes low and will remain low. Every 3 seconds a
ring string is generated and sent over the Receive (Data Out) (Rx) line.
An incoming SMS can be indicated by an Unsolicited Result Code (URC) which causes the
Ring line to go low for 1 second only. Using the AT+CNMI command, the Enabler II-G A-
GPS module can be configured to send or not to send URCs upon the receipt of SMS. See
Enfora GSM/GPRS OEM Module AT Command Set Reference - GSM0102PB001MAN.
1 second 2 seconds 1 second 2 seconds
RING Strin
g
RING Strin
g
Ring
3 seconds
RING Strin
g
RING Strin
g
Ring
3 seconds
RING Strin
g
1 second
URC
Ring
Figure 8 Ring Indicate Timing
6.6.3. Using the Power Control Signal
Figure 9 shows a typical connection to the Enfora Enabler II-G A-GPS module in a machine-to-machine application
using the external PWR_CTL_SIGNAL solution, where there is no external processor controlling the I/O, serial, or
power on/off states. RTC deep sleep functions will NOT function since the PWR_CTL_SIGNAL pin is tied low, the
processor will never stay in a “RTC Sleep” mode. To reset the module, power (BATT) must be cycled. VBAK
must be connected to an uninterruptible power source if RTC time is to be retained.
MLG0208PB001 27 Version1.01 – 10/3/2006