Suppplementary Information For Connecting Profibus Dp - ABB COPA-XE Instruction Bulletin

9.3.7 Suppplementary Information for
Connecting Profibus DP
A Profibus DP Protocol is available among others in the
converter for digital communication. The digital communication
utilizes the RS 485 Data Link.
Transmission format
Transmission speed
Protocol
Ident-No.
Cyclical (output variables, see separate Data Link Description
for COPA/MAG-XE, Part No. D184B093U09)
Terminal Function
+VD VP
A RxD/TxD-N
B RxD/TxD-P
GND C DGND
Cable
A shielded and twisted data cable is recommended.
Max. cable length 1200 m (Cable Type A)
Characteristic impedance 135-165Ω
Max. 32 instruments on a single bus
Baudrate: 9.6-1500 kbit/s
Distributed capacitance <30 pF/m, loop resistance 110 Ω/km
Tap length max. 1 m.
Incoming and outgoing cables on the same terminals.
Fig. 40 Communication Profibus DP
RS 485 Data Link
9.6 to 1500 KBit/s
per EN 50170
6666 HEX
Reference
Supply voltage +5V
Receive/send-data-N
Receive/send-data-P
Data reference potential M5V
Electromagnetic Flowmeter
Bus Terminations for Profibus DP
Both ends of the bus must have bus terminations installed, see
Fig. 41. In addition to the bus termination resistor R2 per the
EIA-RS-485 Standard a resistor R1 (Pulldown) to the data
reference potential GND and a resistor R3 (Pullup) to the plus
supply voltage +VD are to be installed. These two resistors
assure that a defined idle potential exists on the bus when no
participant is transmitting (idle time between telegrams, the
so-called idle status).
For values see DIN 19245, Part 1 and Part 3.
For Cable Type A: R1 = 390 Ω, R2 = 220 Ω, R3 = 390 Ω
Fig. 41 Bus Terminations for Profibus DP, when the Instrument
is Connected at the End of the Bus
COPA-XE / MAG-XE
R1
R2
R3
51