Quickstart Guide
ABB PLC and drives integration using Modbus RTU
Modbus
RTU
‐
36
‐
PLC
and
drives
integration
Read
and
write
more
data
between
PLC
and
drive
(optional)
While
the
already
implemented
function
block
“ACS_COM_MOD_RTU”
has
built
‐
in
functionality
to
read
more
data/parameters
from
pre
‐
determined
Modbus
register
addresses
in
the
drive,
the
function
blocks
“ACS_MOD_READ_N_PRM”
and
“ACS_MOD_WRITE_N_PRM”
can
read
and
write
data/parameters
from
Modbus
register
addresses
according
to
user
choice.
Example
Read
drive
data
with
“ACS_COM_MOD_RTU”
Values
are
read
from
Modbus
register
addresses
40007..
40030.
The
number
of
read
parameters
depends
on
the
function
block
input
“NVAR_READ”.
Configuration
is
for
instance
made
in
parameters
53.12
to
53.17
for
ACS310,
ACS355
and
ACS550,
or
in
parameters
58.35
to
58.58
for
ACS850
and
ACQ810.
The
supported
number
of
parameters
that
can
be
read
in
this
way
depend
on
actual
drive
type,
for
instance
6
parameters
can
be
read
from
ACS355
or
24
parameters
can
be
read
from
ACS850.
Additional
parameter
settings
in
the
drive
are
necessary,
see
example
below
with
an
ACS355
drive:
53.12
=
107
→
Modbus
register
40007
will
consist
of
ACS355
parameter
1.07
DC
voltage.
53.13
=
110
→
Modbus
register
40008
will
consist
of
ACS355
parameter
1.10
Drive
temp.
53.14
=
120
→
Modbus
register
40009
will
consist
of
ACS355
parameter
1.20
Analog
input
1.
Note!
After
these
parameter
settings,
the
drive
needs
a
re
‐
boot
(power
off/power
on)
to
activate
the
settings.
Set
“ACS_COM_MOD_RTU”
block
input
“NVAR_READ”
according
to
number
of
parameters
to
be
read
(1).
Create
a
new
variable
connected
to
block
output
“READ_VALUES”
(2)
and
press
the
“…”
button
(3)
to
set
the
variable
of
type
“ARRAY”
(4)
of
INT.
Give
the
array
Start
index
1
and
End
index
24
(5),
press
OK.
