Main Peripherals; General; The Mw-520 External Ports; Datatac Radio - Motorola Mobile Workstation 520 Application Developer's Manual

42 MW-520 Application Developer's Guide

Main Peripherals

General

The MW-520 External Ports

DataTAC Radio

Creating a Radio Application

The following peripheral devices may be attached to the MW-520 connectors:
• mobile printers
• external speaker
• serial RS-232 communication devices
• DataTAC radio
• iDEN radio
• CDPD radio
• Standard GPS
• Any standard USB drive
• IDB vehicle bus standard
The MW-520 serial external port supports a full set of RS-232 lines. The MW-520
includes one external port (COM1), and additional serial ports can be added by
using USB serial converters.
Using the standard interface for RF communication, you can choose to
communicate directly with the MW-520 internal modem which is a standard serial
device, running on COM3, with a default of 8 bits, no parity, 9600 baud interface.
Options such as handshaking are selectable through the Native Mode interface.
The only difference in the software interface is the COM3 base address, which is
03E8H, and the COM3 IRQ, which is IRQ4. By using Native Mode, you take on
the responsibility of respecting all conventions of the Native Mode protocol and
must personally address any contention between multiple applications (if there are
any). For more information, refer to the Native Mode Interface Reference Manual,
68P04014C90.
When the MW-520 is in Suspend, the RF modem will usually be powered up in
Receive mode. In order to prevent data loss when an outbound message arrives
while the system is in Suspend (wake-up from Suspend can take 5 seconds), it is
recommended to deassert the DTR line before Suspend.
The radio application/driver can detect the Suspend event by waiting for the
Windows
PWR_SUSPENDREQUEST
message. When the Suspend request occurs,