User's Manual

Company Confidential 17 Raveon Technologies
The M7-UC can switch between LPM and normal mode using the DTR line,
and it switches much faster than using the DC power supply. The M7-UC
takes about ½ of a second to power on when DC is applied, but can switch
between normal and LPM in about 25milliseconds.
The factory default value for the ATRP setting is 0. When ATRP is a zero,
the M7-UC will not ever enter the LPM mode, and the DTR input signal is
ignored.
DTR negated means it is a negative voltage. A voltage less than zero volts
applied to DTR will turn the M7-UC off by putting it into LPM.
To assert the DTR signal (turn the modem on), the DTR line must be high (>
3V). DTR is an input to an RS-232 transceiver IC. It is ESD protected, and
is safe for voltages from –20V to +20V input.