User guide

MS-DMT Guide v1.04
Released 05-30-2014
117
APPENDIX E: DATA PORT
The Data Port parameters are locked to 8 data bits, no parity and 1 stop bit and No
Handshaking. The DTR line is asserted to indicate a high PTT state for any applications that
requires the monitoring of the PTT state.
The Data Port support is either accomplished by a paired (null modem) set of Virtual Serial Ports
(VCP) where a server application such as the recommended use of com0com
(http://sourceforge.net/projects/com0com/files/com0com/ ) or other (32 and 64 bit) server
tool is used with the 3rd party terminal software when running on the same PC as MS-DMT. The
use of a signed VCP server is required for Windows 7 and later.
It is recommended that “enable buffer overrun” be selected on both sides of a VCP pair with
com0com or any VCP server that supports this capability to mitigate issues when the terminal
connects and to allow for the use of the MS-DMT tool when the Data Port is not set to 0 and
there is no external terminal program running. VCP servers tested that offer baud rate
emulation do not seem to work, thus the selected baud rates between the MS-DMT and
external software do not seem to matter when using VCP ports as they do when using a physical
RS-232 port. With com0com Microsoft .NET Framework 3.5 is required to use GUI setup seen
below.