42
4.17. Real-Time Clock (RTC)
Real-time clock (RTC) is a source of time for the modem services which require timestamps or compliance
with a schedule to operate. For example, the modem determines time of SMS sending and receiving via RTC
and starts the watchdog timers. RTC configuration is set up in the tab
Settings
Advanced
RTC
of the
ATM Control utility.
When enabled, the modem performs the RTC verification. If there has been the RTC fault, both LEDs glow
for 4 seconds, and the current time is set to 0:00:00.
When the modem is connected to the iRZ Collector server, the modem RTC time is synchronized with it.
4.18. GPIO Pins Operation
To control external devices (for example, sensors), the modem has three configurable GPIO pins (see Fig.
2.7). Pin 1 and 2 can be configured both as "input" and "output"; pin 2 can be configured as ADC. Pin 3 is pow-
er, always operates as an "output".
The modem GPIO is set up in the tab
Settings
Advanced
GPIO
of the ATM Control utility.
4.18.1. Setting Up Pins of an "Input" Type
The pin set to "input" can operate in the normal or inverse modes. In the normal mode the input high level
(level "1") is regarded as an active signal, and the low level (level "0")
– a passive one. In the inverse mode the
modem perceives high input/output signal as an active signal, and low signal
– as a passive one.
To set an action to be performed when an active input signal appears, it is required to specify the operation
algorithm for an input. The signal, coming to input, is a signal of at least 1 second duration.
The input operation algorithm (see 4.1) is set in the tab
Settings
Advanced
GPIO
of the ATM Control
utility.
Table 4.1
Assignments of pins set to input
Input operation algorithm
State at the active
level on input
State at the passive level on in-
put
Code
Function
0
No settings
—
—
1*
Selection of a primary SIM
card.
Primary SIM card
Secondary SIM card
10
Event with SMS sending
Sending SMS message
—
15
Pulse counter**
Counting pulses re-
ceived
—
