EV8000 Datasheet, PDF (28/35 Pages) CML Microcircuits – Evaluation Kit User

Evaluation Kit User Manual for FX828 and FX829
EV8000
Warning: Prolonged window resizing or similar background activities may cause
application warnings or even fatal errors whilst receiving continuous FFSK
messages with small inter-message delays.
1.6.3.23 FFSK Tx Message
Select FFSKTX, TXIDLEM and TXDATAM by clicking on their respective checkboxes and then
click on the Update button. If required, other control bits can be set before Update button is
clicked i.e. baud rate etc.
The user should then enter the number of data bytes to be transmitted in a single message using
the Tx message bytes edit box (2-9). The number of preamble bytes should be entered into the
preamble bytes edit box (2-15). The user has the option of adding a 2-byte checksum to the
message. This can be achieved by checking the Tx Checksum checkbox.
The FFSK Tx message form setup can be stored in memory at any stage by clicking on the
Update button. To transfer the data to the µC board and therefore transmit the FFSK message,
the user should click on the Tx Message Start button.
A checkbox is provided to allow the user to continuously transmit the same FFSK message.
When this checkbox has been checked the user has the option of re-transmitting the 2-byte
synchronisation code. When the Re-Transmit Sync checkbox is checked an inter-message delay
can be specified. The minimum message delay is 100ms, although a value of 0 can be entered to
indicate that no delay is required.
In continuous Tx mode the transmission can be stopped by clicking on the Continuous Tx Stop
button. To indicate that a continuous FFSK transmission is in progress the Tx Message Start
button is disabled until the Continuous Tx Stop button is clicked by the user. Likewise when the
Continuous Tx checkbox is unchecked the Re-Transmit Sync checkbox and Message Delay edit
box are disabled.
Note:
The timer used for the inter-message delay has been implemented in the Windows software.
Therefore, the delay may vary depending on PC performance and other background tasks
running. Whilst operating in continuous FFSK Tx mode with an inter-message delay, it is
recommended that the user disables the Windows Screen Saver and does not attempt any
window resizing, etc.
In continuous FFSK transmit mode with an inter-message delay specified, the delay entered by
the user is the time difference between the end of a message and the start of the next message.
© 2004 CML Microsystems Plc
28
UM8000/4