L1
L2
L3
N
PE
L
N
SMC 144
Power Analyzer
ETH
N
L1
L2
L3
L4
l1 k1 l2 k2 l3 k3 l4 k4
X1
X2
O-
O+
R A1 A2 G B
A
G B/1 A/2
COM1
COM2 / DI
JP
5W
JP
5W
JP
5W
JP
5W
Figure 7: An example of typical installation and wiring diagram for SMC 144.
2.3.3
Peripherals
Function and connection possibilities will be illustrated on an example on figure 8. All peripherals stated below
are galvanically isolated from the rest of the instrument and from each other. Digital inputs shares the same
inputs with secondary RS-485, so they cannot be assembled both.
Primary RS-485
The primary communication line serves for remote reading of actual data, archive downloading and device
configuration. Primary RS-485 line uses terminals
A
,
B
with shielding at terminal
G
of
COM1
block. The final
points of the communication line have to be fitted with terminating resistance.
Digital Inputs (optional)
SMC 144 can be optionally equipped with two voltage sensitive digital inputs.
It uses three terminals in
COM2/DI
block —
G
is common terminal,
B/1
is first and
A/2
is second digital input. Voltage lower than
3 V applied between
G
and digital input
B/1
or
A/2
is evaluated as inactive state, voltage greater than 10 V is
evaluated as active state. On the example picture 8 there are two external switches in series with voltage source
of 24 V
DC
.
Secondary RS-485 (optional)
Optional secondary RS-485 communication line serves for connection of external I/O modules or remote display
unit. Secondary RS-485 line uses terminals
A/2
,
B/1
with shielding at terminal
G
of
COM2/DI
block. The
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