Yokogawa YFGW410 - Manual (Page 196)

<G2. Field Wireless Network>
G2-3
IM 01W02D01-01EN
G2.3 Precautions on Configuring a Wireless
Network
G2.3.1 Route Specification
In the field wireless system constituted from YFGW410 the user can manually configure a wire-
less route for field wireless network. If an error occurs in the communication quality of the speci-
fied route, an alarm message appears on the Field Wireless Management Console.
G2.3.2 Redundancy of Wireless Route
In the field wireless system constituted from YFGW410 the user can configure wireless routes
the user made redundant in advance. If wireless routes are made redundant, even when an error
occurs in either route, a communication is continued via another redundant route, enhancing the
communication reliability.
G2.3.3 Support of Large-Scale Wireless System
In the field wireless system constituted from YFGW410 the user can simultaneously manage
up to 500 field wireless devices and up to 20 field wireless subnets for YFGW410 device (a pair
of the YFGW410 devices in the YFGW410 redundant configuration). A field wireless subnet is
assigned to one of up to 8 hopping patterns to perform operations. No interference occurs in
wireless communications between field wireless subnets with a different hopping pattern. There-
fore, many devices can be arranged in a narrow area by assigning a different hopping pattern to
multiple field wireless subnets.
G2.3.4 Hopping Pattern
A field wireless communication is continued while up to 16 channels are hopped in the speci-
fied cycle. In which sequence channels are to be hopped (hopping pattern) is determined by the
System Manager. A hopping pattern is determined by the setting for each field wireless subnet to
perform operations. If the radio wave accessible ranges of the field wireless subnets assigned to
the same hopping pattern overlap physically, an interference occurs between wireless communi-
cations. When operating multiple field wireless subnets in a place in which the radio wave acces-
sible range overlaps each other, assign a different hopping pattern to each subnet to prevent an
interference between radio waves.
The field wireless system uses the same frequency band as for wireless LAN. When simultane-
ously using wireless LAN in the area in which a field wireless subnet is to be installed, the user
can use the channel black list to disable any channels in the field wireless subnet side to prevent
an interference between radio waves. However, if the number of available channels decreases,
the maximum number of available hopping patterns may decrease.