User's Manual

Page 45
M Series Data Radio – User Manual
© Copyright 2004 Trio DataCom Pty. Ltd.
RF Parameters
This section of the main window permits adjustment of transmitter and
receiver, radio channel modulation scheme, frequency trim and
advanced features.
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 unit and provides warnings if outside an acceptable
range.
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. There are
Port Hardware
The modem acts as Data Communications Equipment (DCE) and has
the following interface signals:
Data Carrier Detect (DCD) - Active when RF carrier is present.
Request To Send (RTS) - TX PTT when RTS active
Receive Data Output (RXD) - Received Data
Transmit Data Input (TXD) - Transmit Data
Part H – TVIEW+ Management Suite - Programmer
• A pre-defined minimum time delay between packets received
at the port. Typically the time delay would reflect the absence
of a couple of characters in the data stream at the specified
user port baud rate.
• Limiting the maximum number of characters which can be put
in the data frame sent over the radio channel.
• Receipt of a selected end of message (EOM) character at the
port. An ASCII carriage return (character 13) is often used for
this purpose.
As each data frame to be transmitted over the radio channel has
overhead data consisting of checksums and SID codes. The
system designer must determine the best compromise between
the ratio of overhead versus user data which depends on packet
size and user data packet transmission latency.
The fields which can be configured are:
•
Character Input timer: Set the input timer value in ms or enter
zero to disable. Range 0 - 255.
•
Maximum Frame Size: Set the maximum number of
characters or enter zero to disable. Range 0 - 4095.
•
EOM Character: Select the check box to the left of the
description to enable and enter the EOM character as a
decimal value. Range 0 - 255.