Data Sheet
World Modem NET
Page 12 of 64
2005 Copeland Communications, Inc.
World Modem NET Datasheet Rev 1.0
Reset – A hardware reset is provided to reset the modem controller on power-up or to force the modem back
to its default settings. This active low signal has an on-board pull up. Leave this pin unconnected if hardware
reset is not needed.
Network Interface
The World Modem NET contains an integrated, self contained Internet engine.
This engine accepts
commands via the serial interface and manages an internet communication session though the modem side.
The Network controller may be used to manipulate TCP/IP and UDP/IP sockets, as well and retrieve Web
server contents over HTTP 1.1. Optional firmware versions are available to sent textual email messages and
use FTP or serve as an Internet to serial router.
The Internet engine is controlled by AT+i commands.
These commands are only available on the serial
interface.
The World Modem NET enters Internet Mode after receiving a command that requires the interface (such as
sending an email or opening a socket). The controller will automatically attempt to initiate a connection and
carry out the requested task. While in this mode, AT+i commands can be used to monitor and control the
process as needed.
The World Modem NET enters Serial Network Mode extends the local asynchronous serial link to a TCP or
UDP socket across the Internet. The primary purpose is to allow simple devices to interact over a network in a
similar fashion as it would normally over a serial channel. The World Modem NET contains a number of
parameters to define the configuration of this interface. These include configuration as a Server or Client.
Reset
The World Modem NET may be reset by either asserting the -RESET signal or via the serial link. To reset
the controller via the serial link, a ‘BREAK’ must be asserted. A ‘BREAK’ signal is issued by transmitting a
LOW (zero) for a period that is longer than 23 bits at the current baud rate. Once a ‘BREAK’ is seen it takes
four seconds to complete the reset cycle.
The World Modem NET also includes an internal Watchdog. When enabled, the watchdog will physically
reset the circuit if a fault is detected. Sending an AT+iWDR forces the watchdog to initiate a reset.
Power
The module is powered by an external 3.3 VDC source. Pins 57 and 61 are tied together internally on 3.3V
models and either or both connected to an external 3.3V supply.
On 5V models, Pin 61 ONLY can be
connected to 5V. Pin 57 may still be used if a 3.3V power supply is required and 5V models are what is
available. There is no on-board regulation of the power supply. The system needs to supply approximately 50
mA of current.
The power pin(s) should be decoupled with a good quality 0.01 F ceramic capacitor and a 1F electrolytic or
tantalum capacitor.
WARNING: ONLY connect one (1) of the power supply pins to either 3.3V or
5V on 5V models.
Connecting both pins 57 and 61 to different power
supplies WILL damage the modem and/or the system it is installed in.
See CCI Common Socket Interface Specification for more details.