Standard Application With 4; Standard Application With Hart Functionality - ABB TTH300 Operating Instruction

s
5.2.2 Standard application with 4 ... 20 mA functionality
Fig. 12
A Transmitter
When connecting these components, observe the following condition:
U
Mmin
Where
U
Mmin
U
Smin
R
Ltg
s
5.2.3

Standard application with HART functionality

Fig. 13
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, the interconnection must have a resistance of ≥ 250 Ω (< 1,100 Ω).
The signal line can be connected with or without grounding. When establishing a ground
connection (minus side), make sure that only terminal side is connected to the equipotential
bonding.
OI/TTH300-EN
Field
A
≤ 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
Field
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 for HART functionality
+
U
M
-
R
Ltg
B Supply isolator / PCS input with supply
Ltg
+
U
M
-
R
Ltg
B Supply isolator / PCS input with supply
+ R )
Ltg 250
TTH300
Electrical connections
Control room
+
U
S
-
B
Control room
R
250 +
U
S
-
B
A00094
A00095
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