ABB 50SM1000, Instruction Bulletin

Page: 35 / 60

29
Electromagnetic Flowmeter Converter
Communication Protocol Profibus DP per DIN 19245
Communication during on-line operation using stadardized
Profibus DP Process Control technology. A list of the supported
communication objects and their definitions can be requested.
The cable types described in DIN 19245, Part 1 and Part 3 are
generally used for this communication technology, see Part 3,
Table 3 and Table 4.
Terminal Designations:
Shield connected to housing
Cable
A shielded and twisted data cable is recommended.
Max. cable length 1200 m (Cable type A)
Characteristic impedance 135-165 Ohm
Max. 32 instruments per segment
Max. 124 instruments on a single bus, total
Baudrate: 9.6-1500 kbit/s
Distributed capacitance <30 pF/m, loop resistance 110
Ω
/km
Max. tap line length 1 m.
In- and outgoing cables connected to the same terminals.
Cable Terminations:
Both ends of the bus cable must be provided with a bus
termination. In addition to the bus termination resistor R2
specified in the EIA-RS-485 Standard an additional resistor R1
(Pull-down) must be connected to the data reference
potential DGND and a resistor R3 (Pull-up) connected to the
supply voltage plus VP. These two resistors are used to define
a specific idle potential on the bus when no participant is
transmitting (idle time between telegrams, the so called
idle-status).
Values see DIN 19245, Part 1 and Part 3.
For cable Type A:
R
1
= 390 , R
2
= 220 , R
3
= 390
For cable Type B: R
1
= 390 , R
2
= 150 , R
3
= 390
GSD File (Instrument Data Base)
The name of the GSD file is ABB_6666.GSD and is included
with the shipment. For a detailed description of the Data Link
see the separate Document ABB Part No. D184B093U03.
Terminal Function Reference
V1
V2
V4
G2
B RxD/TxD-P
A RxD/TxD-N
VP
C DGND Receive/send data - P
Receive/send data - N
Supply voltage Plus P5V
Data refernce potential; M5V
With Bus Termination
W ith Bus
Term inator
PNK
(SPS)
Converter
1
Converter
2
Converter
3
With Bus
Terminator
Fig.12 Bus Termination Profibus DP
Ω Ω Ω
Ω Ω Ω
4
6
A902 A903 A901 A904
3 1S 1 2 2S 3 16 7 6 15 + - M1M3 V5
G2
U2
V1
22
V2
31
V3
A1
V4
A2
V6 44 45 46 P1 P2 P3 P4 L N PE
R1 R2 R3
Fig.13 Bus Termination for Profibus DP, when the Instrument is
Connected at the End of the Bus