Cable Specification; Profibus Dp® Communication - ABB ProcessMaster FEM630 Operating Instructions Manual

FE M63 0 | E L EC TR OM AG N E T I C FLOWM E T E R | O I/F E M6 3 0-EN RE V. A
6 . . .Electrical connections
. . .Digital communication
2
R R
D D
3
1 Modbus master
2 Terminating resistor
3 Modbus slave 1
4 Modbus slave n to 32
Figure 58 Communication with the Modbus protocol

Cable specification

The maximum permissible length is dependent on the baud
rate, the cable (diameter, capacity and surge impedance), the
number of loads in the device chain, and the network
configuration (2 core or 4-core).
• At a baud rate of 9600 and with a conductor cross-
section of at least 0.14 mm2 (AWG 26), the maximum
length is 3280 ft (1000 m).
• When using a 4-core cable as a 2-wire wiring system, the
maximum length must be halved.
• The spur lines must be short, a maximum of 66 ft (20 m).
• When using a distributor with 'n' connections, each
branch must have a maximum length of 131 ft (40 m)
divided by 'n.'
The maximum cable length depends on the type of cable
used. The following standard values apply:
• Up to 20 ft (6 m):
cable with standard shielding or twisted-pair cable.
• Up to 984 ft (300 m):
double twisted-pair cable with overall foil shielding and
integrated earth cable.
• Up to 3937 ft (1200 m):
double twisted-pair cable with individual foil shielding
and integrated earth cables. Example: Belden 9729 or
equivalent cable.
A category 5 cable can be used for Modbus RS485 up to a
maximum length of 1968 ft (600 m). For the symmetrical
pairs in RS485 systems, a surge impedance of more than 100
Ω is preferred, especially at a baud rate of 19200 and above.
1
D
R
A
B
GND
4
PROFIBUS DP® communication
Note
The PROFIBUS DP protocol are not secure, as such the
2
intended application should be assessed to ensure that these
protocols are suitable before implementation
PROFIBUS DP interface
Terminals
Configuration
Transmission
G11603
Baud rate
Device profile
Bus address
For commissioning purposes, you will need a device driver in
EDD (Electronic Device Description) or DTM (Device Type
Manager) format plus a GSD file.
You can download EDD, DTM and GSD from www.abb.com/
flow.
The files required for operation can also be downloaded from
www.profibus.com.
ABB provides three different GSD files which can be
integrated in the system.
ID number
0x9740
0x9700
0x3432
Users decide at system integration whether to install the full
range of functions or only part. Switching is made using the
'Ident Nr. Selector' parameter.
See also Ident Nr . Selector on page 95.
Via the PROFIBUS DP interface or via the local
operating interface in connection with Asset
Vision Basic (DAT200) and a corresponding Device
Type Manager (DTM)
In accordance with IEC 61158-2
9.6 kbps, 19.2 kbps, 45.45 kbps, 93.75 kbps, 187.5
kbps, 500 kbps, 1.5 Mbps
The baud rate is automatically detected and does
not need to be configured manually
Address range 0 to 126
Factory setting: 126
GSD file name
PA139740.gsd 1xAI, 1xTOT
PA139700.gsd 1AI
6xAI, 2xTOT,
ABB_3432.gsd
1xAO, 1xDI, 1xDO
49
V1 / V2
PA Profile 3.02