Endress+Hauser Prosonic S FMU90 - 4.3 Sensor connection

Wiring Prosonic S FMU90 Flow Measurement PROFIBUS
24 Endress+Hauser
3.8 Synchronization line
• If wiring several Prosonic S
(FMU90/FMU95) which are mounted in a
common cabinet and if the sensor cables
run in parallel, the synchronization
terminals (39 and 40) must be
interconnected.
• Up to 20 instruments can be synchronized
in this way.
• The synchronization causes the evaluation
units FMU9x to send the pulses
simultaneously. Only after all sensors have
received their signal, new simultaneous
pulses are sent. This prevents pulses in the
sensor cable of one sensor from
influencing the received signal on the
cable of a different sensor.
• If there are more than 20 instruments,
groups must be formed, each containing a
maximum of 20 instruments. For the
instruments within each group, the sensor
cables may run in parallel. The sensor
cables of different groups must be
separated from each other.
• Usual commercial screened cable can be
used for synchronization
– max. length: 10 m (33 ft) between the
individual instruments
– cross section: 2 x (0.75 to 2.5 mm
2
(18to14AWG))
– for lengths up to 1 m (3.3 ft), an
unscreened cable can be used; for
lenghts exceeding 1 m (3.3 ft),
screening is required. The screen must
be connected to ground.
• Instruments of the Prosonic FMU86x
family can be connected to the
synchronization line as well. In this case a
maximum of 10 instruments can be
connected to each synchronisation line.
L00-FMU90xxx-04-00-00-xx-004
L00-FMU90xxx-04-00-00-xx-017
Prosonic S
FMU90/95
39 40
1
23
20
……
FMU90 FMU90 FMU90
Prosonic S
FMU90/95
39 40
Prosonic S
FMU90/95
39 40
Prosonic S
FMU90/95
39 40
Prosonic
FMU860/861/862
63 64
1
2
10
……
FMU90
VH