ProSoft Technology PS69-DPS - Manual (Page 65)

PS69-DPS ♦ CompactLogix or MicroLogix Platform Reference
Profibus DP Slave Communication Module User Manual
ProSoft Technology, Inc. Page 65 of 108
May 9, 2014
5.1.4 PROFIBUS Interface
Isolated RS-485 interface per EN 50170.
3 RxD/TxD-P Receive/Send Data-P respectively connection B plug
5 DGND Reference potential
6 VP Positive power supply
8 RxD/TxD-N Receive/Send Data-N respectively connection A plug
Please ensure that termination resistors are available at both ends of the cable. If
special PROFIBUS connectors are being used, these resistors are often found
inside the connector and must be switched on. For baud rates above 1.5 MBaud
use only PROFIBUS connectors, which also include additional inductance. It is
not permitted to have T stubs at high baud rates.
Use only a special cable which is approved for PROFIBUS-DP. Make a solid
connection from the cable shield to ground at every device and make sure that
there is no potential difference between the grounds at the devices.
If the PS69 is linked with only one other device on the bus, both devices must be
at the ends of the bus line. The reason is that these devices must deliver the
power supply for the termination resistors. Otherwise the Master can be
connected at any desired position.