Flowserve MX/QX Profibus DP/PA Field Unit - Manual (Page 22)

PB DPV1 / PA Field Unit Installation and Maintenance FCD LMENIM2336-03 – 12/12
22
2.2.5.1 Cable Shielding and Grounding for PROFIBUS PA
For best performance, PROFIBUS PA cables must be shielded. When using shielded cable, connect
each cable shield to the trunk shield, and connect the overall shield to the PROFIBUS power supply
ground.
In Figure 2.9, the grounding point is shown at a connection point of power supply return.
Figure 2.9 – Use of Shielded Cable in PROFIBUS PA
PROFIBUS
Interface
Shielded Wire Pair
Connect Shield
to Ground at one
place only
T T
Field
Device
Field
Device
Field
Device
2.2.5.2 PROFIBUS PA Power Supply
The MX/QX PB/PA board requires a nominal 24 VDC (9-32 VDC) on the PA bus to power the MX/QX
PB/PA board and make the actuator visible on the network. The required power supply is typically
connected to a segment coupler to the bus, usually located at the host end of the cable. Validate the
requirements of the segment coupler to determine actual power and voltage.
NOTE: If the actuator does not have three-phase power and the network is active, the MX/QX PB/PA
board will report this condition to the host.