User's Manual

Boomer II User Manual & Integrator’s Guide _________________________________________________Installation
BM210012WT37 33 Copyright Wavenet Technology © November 2003
Modem Reset Input
The reset input line (HCRESET) is an active low input signal (TTL
compatible) and is fitted with a 6.8kΩ series resistor and clamp diode
to the internal supply line for input protection. Internally it is passively
pulled high (after the series resistor) to the supply rail (3.3V) and is
asserted with an actively driven low signal to ground. The electrical
interface specification and equivalent circuit is as follows:
Reset Input Equivalent Circuit
Reset Electrical Characteristics
Parameter Range Low High
Input Voltage 0-3.3 V OR 0-5V 0.5 V (max) 2.0 V (min)
Input Current 200 µA (max) 200 µA (max)
Pulse width 5mS (min)
Serial Communications Interface
The modem communicates with the controller using the Data Interface
Port connection interface. The asynchronous serial interface on the
Boomer II OEM Modem operates at 3.3V and can be controlled by a
wide variety of micro controllers and microprocessors. The modem can
be connected directly to a micro controller or through a universal
asynchronous receiver/transmitter (UART) to a microprocessor data
bus.
If the modem is to be connected directly to a PC or other RS232
device, an interface must be provided to convert the signal voltage to
the higher values required by an RS232 device.
The protocols supported over this link are the Native Control Language
(NCL), and an emulated Hayes AT compatible protocol. The data
format for both NCL and Hayes is: 8 data bits, no parity, 1 stop bit.
The serial interface lines (RXD, TXD, DCD, DTR, DSR, RTS, CTS,
RI) are TTL compatible. They are fitted with a 33Ω series resistor and
clamp diode to the internal supply line for protection. The electrical
interface capability, equivalent circuit and operation of these lines is
summarized in the tables below: