Panasonic FP2 ET-LAN Technical Manual page 31

If it is impossible to avoid installing the equipment or cables near noise-generating equipment, the
following measures should be taken.
Place the programmable controller, transceiver, and hub inside metal panels.
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Place communication cables inside metal ducts.
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Attach a ferrite core near the ET-LAN unit of the communication cable.
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If using an external power supply terminal (12 V DC) for the ET-LAN unit, attach a ferrite core to the
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power supply cable.
Attach a ferrite core to the power supply cable of the programmable controller (example of ferrite core:
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RFC-10 b Kitagawa Industrial Co., Ltd.).
An alternative measure is to use an optical transceiver close to the noise-generating section of the
equipment and install an optical fiber to keep the noise from affecting nearby equipment. (This is also
effective as a lightning shield for outdoor wiring.)
Caution: Metal panels and metal ducts should be grounded at a grounding resistance of 100 Ω or less.
Also, metal panels and metal ducts should be insulated so that they do not come in contact with
communication devices or cables.
Note:
Installation of LAN cables and devices
A specialist should be consulted concerning construction work such as the installation of 100BASE-TX
and 10BASE-T hubs, the installation of the 10BASE5 (AUI) transceiver, and laying of cables. If this
construction work is done incorrectly, it can adversely affect the entire network, and can cause accidents.
Taking corrective measures through the application
Communication errors occurring in the ET-LAN unit can be minimized by taking the steps outlined below.
Corrective measures should also be taken on the computer side, such as increasing the number of times
that data is sent.
1. Increasing the number of times data is sent
Adjust the "TCP ULP (packet existence time)" and "TCP re-send timer value" parameters in the initial
information setting area, to increase the number of times that data is sent. (See page 5-9.)
When using UDP/IP, the above settings are invalid, so data should be re-sent through the application.
2. Increasing the timeout judgment time
When executing data transmission commands (SEND/RECV), increase the value set for the CPU unit
system register No. 32. (See page 13-24.)
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