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Docklight V2.2 User Manual 07/2016 Copyright 2016 Flachmann und Heggelbacher GbR
Glossary / Terms Used
11.21 UART
Universal Asynchronous Receiver / Transmitter. The UART is the hardware component
that performs the main serial communications tasks:
- converting characters into a serial bit stream
- adding start / stop / parity bits, and checking for parity errors on the receiver side
- all tasks related to timing, baud rates and synchronization
Common UARTs are compatible with the 16550A UART. They include a 16 byte buffer
for incoming data (RX FiFo), and a 16 byte buffer for outgoing data (TX FiFo). Usually
these buffers can be disabled/enabled using the
Windows
Device Manager and opening
the property page for the appropriate COM port (e.g. COM1).
11.22 Virtual Null Modem
A virtual null modem is a PC software driver which emulates two serial COM ports that
are connected by a
. If one PC application sends data on one virtual
COM port, a second PC application can receive this data on the second virtual COM port
and vice versa.
By using a virtual null modem driver on your PC you can easily debug and simulate
serial data connections without the use of real
Virtual COM connections do not give you the same timing as real RS232 connections
and usually do not emulate the actual bit-by-bit transmission using a predefined baud
rate. Any data packet sent on the first COM port will appear in the second COM port's
receive buffer almost immediately. For most debugging and simulation purposes this
limitation can be easily tolerated. Some virtual null modem drivers offer an additional
baud rate emulation mode, where the data transfer is delayed to emulate a real RS232
connection and its limited transmission rate.
For an Open Source
Windows
software that has been successfully tested with
Docklight, see
http://com0com.sourceforge.net/
11.23 Wildcard
A wildcard is a special character that serves as a placeholder within a sequence. It may
be used for
when parts of the received data are unspecified, e.g.
measurement readings reported by a serial device. Wildcards can also be used to
support parameters in a
The following types of wildcards are available in Docklight:
Wildcard '?' (F7)
: Matches exactly one arbitrary character (any ASCII code between 0
and 255)
Wildcard '#' (F8)
: Matches zero or one character. This is useful for supporting variable
length command arguments (e.g. a status word) in Send / Receive Sequences. See
Checking for sequences with random characters
Sending commands with parameters
for examples and additional information.
Other placeholders that allow random data:
Function Character '!' (F12)
: Bitwise comparison. This is useful if there are one or
several bits within a character which should be tested for a certain value. See
Содержание Docklight V2.2
Страница 1: ...Docklight V2 2 User Manual 07 2016 Copyright 2016 Flachmann und Heggelbacher GbR...
Страница 5: ...Copyright...
Страница 7: ...Introduction...
Страница 11: ...User Interface...
Страница 14: ...Features and Functions...
Страница 17: ...Working with Docklight...
Страница 28: ...Working with Docklight Advanced...
Страница 41: ...Examples and Tutorials...
Страница 46: ...Reference...
Страница 62: ...Support...
Страница 64: ...Appendix...
Страница 76: ...76 Docklight V2 2 User Manual 07 2016 Copyright 2016 Flachmann und Heggelbacher GbR Appendix...
Страница 77: ...Glossary Terms Used...