IM 12A06S01-00EN-P
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2.3.3 Wireless connection
In laboratory environments the HOST Fieldmate system can be connected to the SA11
using the Yokogawa Bluetooth device model IB100. Interconnection in between the IB100
and SA11 is done using the WU11 type S interconnection cable with at both ends a M9
connector. The wireless communication in between the Fieldmate system and IB100 is
limited to a distance of 10 meter.
Grounding
The measuring system must always be
connected to a class D ground (a ground
resistance of 100 Ohm or less), preferably
done at the HOST side. To protect the
SA11 device against interference, such as
electromagnetic noise or common mode, all
wires in WU11 type -S cable are connected
at HOST. This makes the housing of the
SA11 grounded. For correct measurement
without loss of specifications, it is strongly
recommended to ensure that the process
liquid is grounded. Figure 2.4 shows the
connection diagram in case without/UM
option.
However, in case that there is different
potential between Ground at HOST side and
Ground which the housing of the SA11 is
connected, figure 2.5 shows the example
of the installation. To prevent ground loop
by this different potentials it is necessary to
disconnect one of the ground references.
This can be done at the HOST side by
disconnecting the wire #82 of the WU11 type
S cable. Please connect #82 to NC terminal
on the SENCOM SA module when SA11 is
connected to FLXA402. Please be sure to
insulate contact pin of #82 wire from terminals
and metal housing, when SA11 is connected
to other host. The SA11 device must then
be installed using the optional pipe and wall
mounting hardware (/UM) with a ground wire
connected in between the ground terminal
of the mounting bracket and the ground
reference of the process.
Alternate way to prevent ground loop is
to isolate the SA11 & mounting plate from
ground 2 & keep the terminal 82 connected.
Remark: For the installation shown in Figure
2.5, in case the ground references at the
HOST side (Ground 1) and process side
(Ground 2) have no potential difference the
Host
WU11
(max 10m)
Ground
WE10
(max 3m)
SA11/UM
Sensor
Liquid
IB100
Figure 2.6: Installation example
SA11 & IB100 to prevent interference
Ground 1
#82
Host
WU11
(max 100m)
Ground 2
WE10
(max 3m)
SA11/UM
Sensor
Liquid
Figure 2.5: Typical installation example
to prevent ground loop
Host
Ground 1
Sensor
SA11
WU11
(max 100m)
Liquid
Ground 2
Figure 2.4: Typical installation of
SA11 to host