Connecting Cable - ABB 261GS Operating Instruction

Change from two to one column
Fig. 11: "Point-to-point" communication mode
1 Pressure transmitter | 2 Possible connecting points for a modem between A and B | 3 Power supply unit | 4 FSK modem
Fig. 12: "FSK bus" communication mode
1 FSK bus | 2 Supply module with HART isolation | 3 FSK modem
Change from one to two columns
5.6

Connecting cable

Communication between the transmitter and PC or laptop is
only possible if the cabling meets the following requirements:
The minimum wire diameter depends on the line length.
Line lengths up to 1,500 m: 0.51 mm
Line lengths above 1,500 m: 0.81 mm
The maximum line length is limited.
Dual-core cable: 3,000 m
Multi-core cable: 1,500 m
1
2
+
p
U
B
+
#
–
2600T
4
RS 232C
+
p
U
B
+
#
I + FSK
2600T A
+
p
U
B
+ #
I + FSK
A
2600T
3
R
+
U
S
–
I + FSK
A
+
4 & 20 mA
R
U
S
1
2
+
4 & 20 mA
R
U
S
1
2
RS 232C
3
The actual possible line length of the electrical circuit depends
on the total capacitance and total line resistance, and can be
estimated using the following formula:
6
C
65 x 10 
f
1000
 
L
RxC C
L = Line length in m
R = Total line resistance in Ω (ohms)
C = Line capacitance in pF/m
C = Capacitance of the devices located in the circuit in pF
f
Avoid routing cables with other electrical cables (with inductive
load, etc.) or near large electrical equipment.
M10693
M10694
261Gx, 261Ax | IM/261Gx/Ax-EN Rev. 08 19