e
Nod3-
C
Digital Transmitter
e
Nod3-
C
:
User’s instructions
NU-eNod3C-E-0911_165702-I
19/22
- a duration prior to an edge on an input assigned to ‘s
top checkweigher cycle
’
(Fig.8).
Caution, only input 2 is operational if both inputs are assigned to the
‘stop
checkweigher cycle’
function.
e
Nod3-
C
automatically calculates a result corresponding to the object weight. This result value
may be weighted by a coefficient.
A value image of the quality of the result is also determined. This value is the standard deviation of
the measurements acquired during the measurement time. A low value means a good
checkweigher result.
Each cycle is counted and the following statistical data are updated for each new complete cycle:
- results
average
-
running total (results sum)
-
number of cycles
- standard
deviation
e
Nod
View
can be used to determine stabilization and measurement times so as to optimize
parameters. (See
e
Nod
View
user’s instructions documentation).
11.2 Providing the result value :
11.2.1 Outputs
synchronization:
Two specific functions may be assigned to
e
Nod3-
C
logical outputs so as to synchronize the result
reading:
-
‘cycle in progress’
: this function causes the output to be set active from the beginning to
the end of the cycle (at the end of the
‘measuring time’
or when a ‘
stop checkweigher cycle’
input is activated).
-
‘checkweigher result available’
: this function causes the output to be set active when a
cycle is complete. In
ModBus
and
CANopen®
protocols, it remains in this state until the
beginning of a new cycle or until a
‘clear’
request. In
SCMBus
protocol, the output state
changes when it is read.
11.2.2 With the SCMBus protocol:
- In
‘Checkweigher automatic transmission’
mode, when the cycle is finished, the result is
automatically sent through the serial line. After the transmission, the measurement result is
set to
????????
.
- In
‘Checkweigher transmission on request’
mode, the measurement result has to be read.
Reading automatically resets measurement memory to
????????
. Starting of a new cycle
induces also a reset to
????????
. The measured result can also be cancelled (set to
????????
) without reading. It can be done by an input assigned to ‘
clear
’ or by the
‘clear’
command.
11.2.3 With
the
ModBus protocol:
- As soon as the measurement result is available, it can be read. Starting a new cycle
cancels the previous measurement result (set to ‘
FF FF FF FF’
).
The measurement result can also be cancelled (set to ‘
FF FF FF FF’
) before a new cycle is
started. It can be done by an input assigned to
‘clear
’ or by the ‘
clear’
command.
11.2.4 With the CANopen® protocol:
- As soon as the measurement result is available, it can be read. Starting a new cycle
cancels the previous measurement result (set to ‘
FF FF FF FF’
).
The measurement result can also be cancelled (set to ‘
FF FF FF FF’
) before a new cycle is
started. It can be done by an input assigned to
‘clear
’ or by the ‘
clear’
command.
- The result transmission can be triggered in different ways. It depends on the chosen trigger
event (see document Ref. 165 717).
11.3 Management of Set-points:
Outputs may be assigned to the set-point function. Set-points are triggered by the measurement
result (fig. 9). As long as checkweigher result is not available (
????????
) or (
FF FF FF FF
), it is
seen like a value < to set point.
Set points can also be assigned to the checkweigher running total value (cumulated weight).
