Fluke 19xC-2x5C
Users Manual
A-6
Foundation Fieldbus H1 31.25 kBits/s.
Is used to control ‘field equipment’ such as sensors,
actuators, valves, and I/O devices via a two-wire
connection. The system allows two-way communication
between controller and the devices. Data traffic is
continuous. The wires are marked + and – and carry a
DC supply of about 24 Vdc with superimposed data of
about 800 mVpp. The figure below shows the bus
structure.
To check Foundation Fieldbus, ScopeMeter Channel A is
on and alternately AC coupled for data or DC coupled to
test 24 Vdc. The recommended probe is the Fluke 10:1
probe.
Connect the probe as shown below.
DATA +
DATA -
Suitable measuring spots are the screw terminals that are
present in a system’s junction boxes. If preferred, you can
use the TP88 Back Probe Pins (optional) to probe these
terminals at the wire entry point. Commonly used wire
colors are orange for + and blue for –.
Probe A
GND A
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