User's Manual

Page 47
E Series Data Radio – User Manual
© Copyright 2005 Trio DataCom Pty. Ltd.
Disabled
This selection disables the DCD output on the port. This selection
is not permissible if hardware based flow control has been
selected.
RF Carrier Detect
This selection causes DCD to be asserted at the onset of a
received RF signal being detected. This will generally occur several
milliseconds before data is transmitted from the port.
Data Detect (RS485 Flow Control)
This selection causes DCD to be asserted when data is about
to be transmitted from the port. This option is not available if
handshaking is set to “None” or “Xon/Xoff”.
RF Parameters
This section of the main window permits adjustment of transmitter
and receiver, radio channel modulation scheme, frequency trim
Transmitter
The transmitter can be configured for transmit frequency and
power level.
Frequency
The required transmit frequency in MHz can be entered in the
display field. The programmer checks that the selected frequency
is in the range for the particular model of radio and provides
warnings if not.
Power Adjust
The currently selected transmit power is displayed below the button
in dBm. The power level can be adjusted by selecting this button
which displays a dialogue box. The up/down keys, or a typed in
value, can be used to select the required power level in dBm steps.
Part I – TVIEW+ Management Suite - Programmer
• DSR
DSR is permanently set to TRUE.
• CTS
The CTS is a signal from the modem to the host informing the
host that the modem is able to accept incoming data on the
TXD line. It responds to the actions of the RTS line similar to
the operation of a “standard” line modem.
The CTS is FALSE if the RTS line is FALSE. Once the RTS
line is set to TRUE (signalling that the host wants to send
some data to the modem on the TXD line), then the CTS
will be set TRUE within 1ms, if the modem is capable of
accepting more data.
The CTS line will be set to FALSE if the transmit buffer in the
modem exceeds 4075 bytes, or the number of queued frames
exceeds 29 to ensure that no overflow condition can occur.
• RTS
The RTS line is used for two reasons. The first is to assert
the CTS line in response to RTS. The RTS line can also be
used to key up the transmitter stage of the modem.
• DTR
The DTR line is used for flow control of data being sent from
the modem to the host controller. When the host is able to
accept data it sets this line to TRUE, and if data is available
within the modem, it will be sent to the host. If the host
cannot accept any more data, then it sets the DTR to FALSE,
and the modem will stop all transmissions to the host.
• Xon/Xoff
If the flow control mechanism is XON/XOFF then
the modem uses the standard ASCII control codes
of DC1 {^Q=11(Hex)=17(Dec)} for XON and DC3
{^S=13(Hex)=19(Dec)} for XOFF. The DTR input line is totally
ignored.
Note: There is no substitution mechanism employed in the
XON/XOFF protocol, so care must be taken when transferring
binary data to ensure that invalid flow control characters are
not generated.
Advanced
This button provides access to the advanced features of the
port configuration. When selected a dialogue box appears which