Electrical connections
s
4.5.2
HART functionality
Fig. 14
A Transmitter
Adding resistance R
U
Mmin
Where
U
Mmin
U
Smin
R
Ltg
R
250
For HART functionality, use supply isolators or PCS input cards with a HART mark. If this is not
possible, a 250 Ω (< 1100 Ω) resistor must be added to the interconnection.
The signal line can be operated with or without grounding. When establishing a ground
connection (minus side), make sure that only one side of the terminal is connected to the
equipotential bonding.
s
4.5.3
PROFIBUS PA and FOUNDATION Fieldbus H1 functionality
Fig. 15
A Transmitter
When connecting these components, observe the following condition:
U
Mmin
Where
U
Mmin
U
Smin
R
Ltg
24 - EN
Panel
A
increases the minimum supply voltage:
250
U
+ 0.022 A x (R
Smin
:
Minimum operating voltage of transmitter
:
Minimum supply voltage of supply isolator / PCS input
:
Line resistance between transmitter and supply isolator
:
Resistance of resistor for HART functionality
Panel
A
U
+ 0.012 A x R
Smin
:
Minimum operating voltage of transmitter
:
Minimum supply voltage of supply isolator / PCS input
:
Line resistance between transmitter and supply isolator
+
U
M
-
R
Ltg
B Supply isolator / PCS input with supply
+ R
)
Ltg
250
+
U
M
-
R
Ltg
B Segment coupler
Ltg
TTF300
Control room
R
250
+
U
S
-
B
Control room
+
U
S
-
B
A00095
A00094
CI/TTF300-X1