Precautions For Fl-Net Use - Hitachi FL.NET User Manual

7 TROUBLESHOOTING

7.3 Precautions for FL-net Use

For the FL-net transmission path requirements, see the aforementioned section or IEEE802.3
standard. In addition to such requirements, you must observe the FL-net-specific precautions.
• Ensure that no other Ethernet communication data flows along the FL-net communication cable.
• Do not connect the FL-net to a router.
• The use of a switching hub for the FL-net does not produce any beneficial effect.
• The use of infrared, radio, or like medium may substantially decrease the real-time capability of
communications.
• When you use a personal computer, the real-time capability of communications may
substantially change depending on the personal computer capacity and the employed OS and
applications.
• Use a specified IP address only. The same network address must be used (the standard
network address is 192.168.250.). For the node number (station number) for the IP address,
the following input range is recommended. When a node number is set, it is not checked for
duplication until it is actually used for communication. If a duplicate node number is used for
communication, a node number duplication error occurs. Exercise care not to set a duplicate
node number.
• Make a proper ground wire connection. Ensure that the employed ground cable has a
sufficient thickness.
• Ensure that the FL-net is positioned at an adequate distance from a noise source. Also, avoid
installing the FL-net together with a mains power line or the like.
• When cyclic data communication and message data communication are simultaneously
effected, the real-time capability may deteriorate depending on the data amount and the like.
• Cyclic data communication areas (common memory areas) need not contiguously be allocated.
• The regular communication capability depends on the processing capacities of the connected
devices. The entire communication is effected with the communication processing speeds of
all the networked devices adjusted for the slowest device's communication processing
capability (minimum permissible frame interval). Therefore, the connection or addition of a
single device may significantly deteriorate the real-time capability of the entire system.
• Although the header section of message data communications is in big-endian format, the data
section is in little-endian format. Note, however, that the system parameters in the data section
for a profile read are in big-endian format (the use of the big-endian format transmits the MSB
first).
Network address
192.168.250.
7-6
Node number
1 to 249