Specifications

Digi m10 Hardware Reference v 1.20
Digi International, Inc. © 2009
Page 12 of 36
2.2 Serial Interface
The main serial interface provides device management and monitoring using 3.3 V levels. The
serial data is carried on the Transmit (TX) and Receive (RX) lines. The details of the Transmit
and Receive pins are shown in
Table 2. An RS232 level shifter is required to connect the Digi
m10 to a PC. This is already available on the development board, which comes with the Digi m10
JumpStart Kit.
Table 2: Transmit and Receive Pins
Pin
Name
Description
8 TX 3.3 V RS232 interface; Digi m10 to the host controller
7
RX
3.3 V RS232 interface; host controller to the Digi m10
2.3 Power and Ground
The Digi m10 is powered using five pins of its 14-pin connector (see Table 3). The five mounting
pins on the shield of the Digi m10 are also connected to the ground plane of the Digi m10.
Table 3: Power Pins
Pin
Name
Description
1
VCC
Supply
2 GND Ground
3 VCC Supply
4 GND Ground
6 GND Ground
2.4 Power Enable
The Power Enable signal is used to turn the Digi m10 ON or OFF. It is an active high logic-level
signal. The power enable signal can be from 3V min to 18V max. This will help users who do not
want separate PWR_EN functionality as they can tie PWR_EN to the Digi m10 supply voltage.
However, in this condition, the Digi m10 will be always be powered ON (consuming receive
current) unless the user cuts OFF Digi m10 power. This signal has to be maintained at an active
high level in order to keep the Digi m10 ON.
Table 4: Power Enable Pin
Pin
Name
Description
5 PWR_EN Digi m10 Power Enable
This line is pulled low using a 47KΩ resistor.