Digital Communication - ABB VA Master FAM540 Inbetriebnahmeanleitung

Error message on the LCD display
Automatic system monitoring with error diagnostics in plain text on
the LCD display.
Data security
Automatic saving of the totalizer values and application conditions
using EEPROM at shutdown or when supply voltage fails (over
10 years).
Terminal connection diagram
a) Auxiliary power from central power supply
2
Functional ground
Fig. 12
b) Auxiliary power from power supply
2
Functional ground
Fig. 13
1 Power supply unit
2 FAM540
U = Operating voltage
B
U = Supply voltage
S
R = Max. allowable load for power supply (e.g., indicator)
B
R = Max. allowable load for output circuit is determined
by the power supply
Auxiliary power (supply voltage)
Standard: 10 ... 46 V DC
Ex design: 10 ... 30 V DC (see chapter "Ex relevant specifications").
Residual ripple: max. 5% or ±1.5 V
R [k ] Ω
B
1.5
1
0.5
0.25
10 V 15.7 V
Fig. 14: Current output load diagram
Current output load
Min. > 250 Ω, max. 1500 Ω (with I on alarm = 23.0 mA)
CI/FAM540-X1
U U
B S
31
32
R
B
42
41
U
U
B S
31
32
R
B
1
42
41
ss
21.5 V 33 V 46 V
VA Master FAM540
Cable
Max. cable length 1500 m, AWG 24 twisted and shielded.
To ensure full EMC protection, the cable shield must be connected to
the internal ground terminal as shown in Fig. 15:
Fig. 15
G00418
Power consumption
< 1 W
Temperature influence on current output
≤ 8 µ A/K
For the hazardous area design, see chapter "Ex relevant
specifications".
R
Ko
3.4.3

Digital communication

Communication HART protocol
G00419
The HART protocol is used for digital communication between a
process control system or PC, a handheld terminal and the FAM540.
All meter and measuring point parameters can be transmitted. In
reverse direction, the integrated converter can also be configured in
this manner.
The digital communication utilizes an AC signal superimposed on the
analog current output (4 ... 20 mA) that does not affect any meters
connected to the output.
HART communication is performed via FSK modem with point-to-
point or multidrop operation.
Transmission method
FSK modulation at current output of 4 ... 20 mA based on the Bell
202 standard. Max. signal amplitude 1.2 mA
Functional ground
Fig. 16
1 Bell 202 modem
R Min. = 250 Ω, max. = 1500 Ω
B
U [V]
B
G00420
Functional ground
Fig. 17
Installation
G00901
.
SS
Current output terminals
Hart R Hart ≥ 250 Ω
(supply voltage)
Switching output terminals
(Prog. output)
EN - 15