BRONKHORST
®
Page
8
FlowDDE
9.17.067
3
PARAMETER
INFORMATION
FLOW
‐
BUS
is
used
for
parameter
value
exchange
between
instruments
and
operation
modules
(keyboard
or
PC
‐
interface).
Parameter
information
consists
of
several
properties
for
behaviour
within
the
FLOW
‐
BUS
system.
In
the
‘parameter
properties’
table
you
will
find
a
list
of
parameters
and
their
properties.
In
the
‘parameter
values’
table,
the
values
are
described
more
detailed.
This
list
consists
mostly
of
parameters
for
mode
settings.
Property
description
in
parameter
properties
table
Item
Description
Parameter(DDE)
Unique
parameter
number
(also
used
for
DDE
‐
communication:
P(x)).
Name
Name
of
the
parameter,
used
for
parameter
identification.
Process
Process
where
parameter
is
used
on
FLOW
‐
BUS
module, used
for
communication
directly
through
RS232.
When
empty
in
the
table,
the
process
has
to
be
determined
from
the
FLOW
‐
BUS
system
information
(for
parameters
located
in
more
than
one
process,
e.g.
setpoint,
measure).
FBnr(parameter)
Parameter
number
in
process
on
FLOW
‐
BUS
module, used
for
communication
directly
through
RS232.
Type
Variable
type
of
the
parameter
c
(unsigned)
char
1
byte
value
0..255
when
StrLen
is
0
c
string
Multiple
bytes
when
StrLen
is
other
than
0
i
(unsigned)
integer
2
bytes
value
0..65535
f
float
4
bytes
value
+
‐
1.18E
‐
38..+
‐
3.39E+38
(IEEE
‐
floating
point
notation)
l
(unsigned)
long
4
bytes
value
0..4294967295
data
types
>
1
byte
are
MSB
first.
StrLen
Length
of
string
in
bytes
(characters)
used
in
combination
with
Type
c
for
strings
‐
2
indicates
that
a
string
is
zero
‐
terminated,
not
defined
in
length,
but
until
the
first
0
‐
char.
X
indicates
a
string
with
a
length
of
X
bytes
0
means
no
info
required
(not
a
string
type
parameter)
Min
Minimum
value
of
parameter
allowed
when
parameter
is
read/written.
The
value
will
be
checked
on
this
limit
(error
when
out
of
limit).
Max
Maximum
value
of
parameter
allowed
when
parameter
is
read/written.
The
value
will
be
checked
on
this
limit
(error
when
out
of
limit).
Read
Indication
if
parameter
is
allowed
to
be
read
via
FLOW
‐
BUS.
Write
Indication
if
parameter
is
allowed
to
be
written
via
FLOW
‐
BUS.
Poll
Indication
if
parameter
should
be
polled
continuously
by
FlowDDE in
order
to
keep
the
(changing)
parameter
value
up
to
date.
Advanced
Indication
if
parameter
is
for
advanced
users
only.
These
are
mainly
parameters
for
maintenance/service.
Secured
Indication
if
parameter
is
secured
for
use
through
FLOW
‐
BUS.
Reading
this
parameter
is
possible,
but
changing
it
needs
special
handling.
High
security
Indication
if
parameter
is
highly
secured
(only
few
parameters).
Reading
this
parameter
is
possible,
but
changing
it
needs
special
handling.
Description
Short
description
about
the meaning
of
parameter
or
where it
is
used
for.
DDE
str
Parameter
DDE
string
(max.
10
characters).
This
becomes
the DDE
value
when
parameter
is
not
available
on
instrument.
Also:
until
FlowDDE
V4.58
used
for
parameter
identification.
Changing
parameter
values
is
possible
when
a
parameter
is
not
read
‐
only
and
not
secured.
The
range
and
type
of
parameters
are
described
in
the
tables.
When
parameter
values
are
out
of
range
they
will
be
either
'clipped'
on
the
nearest
value
allowed
or
you
will
get
an
error
message:
'parameter
value
error'.
(FlowDDE)
Parameter
numbers:
All
parameter
information
is
referenced
to
the
parameter
number.
This
is
a
unique
number
for
a
parameter
to
avoid
redundancy.
These
numbers
are
needed
for
DDE
communication
only.
