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Ver.1.1
11.4 Headerless Packet Transmission Mode
11.4.1 Input data
In headerless packet transmission mode, up to 150 bytes of message can be stored in the transmission buffer,
and transmission starts when the total length of the messages stored in the message buffer exceeds 26 bytes.
If many messages are input successively, the message buffer may become full because wireless transmission
cannot keep pace with message input, and some messages may be lost. If such an event occurs, enable the
hardware flow control. You are recommended to specify "Enabling response" also in headerless packet
transmission mode since, with this setting, you can confirm the success or failure in message transmission with
each response.
11.4.2 Measures against packet loss
(1) Messages exceeding 26 bytes
If messages not less than 26 bytes in total are input successively, transmission of some messages input
earlier may fail. To prepare for such an event, check each response on the sender FDP02 to prevent the
loss of messages, and create messages so that the loss of packets can be determined on the receiver
FDP02.
(2) Setting of serial communication speed
If different serial communication speeds are set on the sender FDP02 and the receiver FDP02, the loss of
data may occur on the FDP02 configured with a slower speed than that of the other FDP02. Therefore,
you are recommended to set the same serial communication speed on all FDP02s.
11.5 Occurrence of Data Loss Even under Hardware Flow Control
If the FDP02 is connected to a personal computer and a specific software program created on the personal
computer is used, the data output from the personal computer to the FDP02 does not stop immediately even
when the input to the FDP02 is disabled by hardware flow control. In such cases, the data output from the
personal computer may be lost.
11.6 Frequency Setting in Multi-System Environment
If multiple FDP02 systems are operating, set the radio frequencies that are apart from each other at least by 2
MHz on individual FDP02s. If adjacent communication channels are set on different FDP02s, interference
may occur and disable the FDP02s to communicate.
11.7 Timing of Command Input
When entering multiple commands successively, wait, after entering a command, until the P0 response for the
entered command is received before entering the next command. If the next command is entered before the
P0 response for the preceding command is received, an error occurs or the entered next command is ignored.
11.8 INI and RST Commands
After executing the INI or RST command, always check that the P0 response is returned. Turning off the
power of the FDP02 before the P0 response is returned may damage memory registers. If the return of P0
response cannot be checked, for example, in case that the baud rate has been initialized, wait for 520 ms or
more after entering the INI or RST command, and then turn off the power.
11.9 Power-Down Mode
Switching the FDP02 to the power-down mode (by setting the /SHUT pin to the low level) while registers of
the FDP02 are being accessed may delete the settings in the registers. To avoid this problem, do not control
the /SHUT pin while the REG command is being executed.
Releasing the FDP02 from the power-down mode clears the parameter settings in registers that were made
with commands before the FDP02 was set into the power-down mode. Change the parameter settings before
using the power-down mode, or make the parameter settings again after releasing the FDP02 from the
power-down mode.
The FDP02 returns to the normal operation in a maximum of 120 ms after the FDP02 is released from the
power-down mode.
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