User's Manual

Page 10 FRH-SD07TU/TB Manual
accidental damage to the system and unexpected operation and/or
injury.
In addition to this manual, read the operation manual of a PC (Personal
Computer) and PLC (Programmable Logic Controller) to be connected.
re the cable connections correctly. Incorrect wiring can
damage the system, causing it to malfunction and/or create a shock and
lock
vided with the connector of this equipment, never stretch
the cable or pull it up by hands.
2.3 Pow er Supply Precautions
Since FRH-SD07TU/TB contains a very-high-frequency sensitive analog circuit, the modem
is susceptible to be affected the variation of the power source and noises from the digital
ci
pow
used the power source line is enough below
than the practical level in the following way.
• Prepare 2 units of FRH-SD07TU/
y to the same and fixed frequency as below.
Example: @FRQ:H00 CR/LF
• Set the number of retransmission count of the modem on the sender side to 0. 
Example: @RNO000 CR/LF
everal hundreds times. If almost all responses are “P0”
.
be a noise
• However, there is a possibility of causing communication failure due to a trouble in the
ica ed to
repeat the above c
ET
Be sure to wi
fire hazard. Also insert the cable firmly to the connector. Since no
system is pro
rcuit. Therefore, when embedding the modem into the system, it is necessary to supply
er to the modem from a different (independent) power supply IC chip other than those
in the digital circuits. Check the noise level from
TB mounted in the system
of each modem• Set the frequenc
• Issue the @TXT command s
(communication success), there is no problem
• If “N1” response (communication failure) returns many times, there may
problem in the power source.
radio commun
CAUTION
WA RN I NG
tion channel (multipath). For correct judgment, it is recommend
hecking several times.
For the operation of commands explained, refer p.79 COMMAND S
DESCRIPTION.
Rev. 050415-01.1