Scaime eNod3-C User manual

eNod3-C
Digital Transmitter
eNod3-C: User’s instructions
NU-eNod3C-E-0911_165702-I
1/22
User’s instructions

eNod3-C
Digital Transmitter
eNod3-C: User’s instructions
NU-eNod3C-E-0911_165702-I
2/22
Document revisions
version date description
A 01/07 -creation
B 05/07 -layout modification
C 11/07 -CANopen® protocol comatibility / RS/CAN jumper
D 02/08 -CANopen® communication full description
-checkweigher statistical datas presentation
E 04/08 -new inputs assignement : allow new cycle and peak
detection cycle decription modified
F 11/08
-document title modified (eNod3 => eNod3-C)
-band-stop filter and automatic zero correction in
checkweigher descriptions added.
G 09/09
-new hardware design
-logical inputs wiring examples
-instructions for use in legal for trade applications
added.
H 11/09 -document title modified
-reference to a use in an AWI
I 07/11
-Determination of the weight : Checkweigher result
quality value added
-checkweigher zero automatic correction;

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Digital Transmitter
eNod3-C: User’s instructions
NU-eNod3C-E-0911_165702-I
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1GENERAL PRESENTATION:.............................................................................. 4
1.1 Dimensions: ..................................................................................................................................... 4
1.2 General characteristics: ................................................................................................................... 5
2INTERFACES: ..................................................................................................... 7
2.1 Connection to the power supply: ..................................................................................................... 7
2.2 Connection to load cell(s): ............................................................................................................... 7
2.3 Connection of Inputs & Outputs:...................................................................................................... 8
2.3.1 Digital inputs .......................................................................................................................... 8
2.3.2 Digital outputs........................................................................................................................ 8
2.4 COMMUNICATION INTERFACES:................................................................................................. 9
3COMMUNICATION:............................................................................................. 9
3.1 ModBus RTU: ................................................................................................................................ 10
3.2 SCMBus:........................................................................................................................................ 10
3.2.1 Fast SCMBus format: .......................................................................................................... 10
3.3 CANopen®..................................................................................................................................... 10
4USE IN LEGAL FOR TRADE APPLICATIONS :............................................... 11
4.1 Introduction .................................................................................................................................... 11
4.2 Legal for trade parameters ............................................................................................................ 11
4.3 Sealing ........................................................................................................................................... 11
4.3.1 Physical sealing :................................................................................................................. 11
4.3.2 Software sealing :................................................................................................................ 11
4.4 Specific requirements : .................................................................................................................. 11
5CALIBRATION................................................................................................... 12
5.1 Calibration types: ........................................................................................................................... 12
5.2 Linearization correction:................................................................................................................. 12
6INPUTS FUNCTIONING: ................................................................................... 13
6.1 Assignment of inputs: .................................................................................................................... 13
6.2 General functions:.......................................................................................................................... 13
6.3 Functions attached to an operating mode: .................................................................................... 13
7OUTPUTS FUNCTIONING: ............................................................................... 14
7.1 Assignment of outputs: .................................................................................................................. 14
7.2 General functions:.......................................................................................................................... 14
7.3 Functions attached to an operating mode: .................................................................................... 14
8SET POINTS:..................................................................................................... 15
9FILTERS: ........................................................................................................... 16
10 TRANSMITTER OPERATING MODE:............................................................ 17
10.1 Measurement reading request:...................................................................................................... 17
10.1.1 Single measurement transmission: ..................................................................................... 17
10.1.2 Continuous measurement transmission: ............................................................................. 17
10.2 Specific commands through an input:............................................................................................ 17
10.2.1 Transmit measurement (fig. 4) ............................................................................................ 17
10.2.2 Measurement window (fig.5) ............................................................................................... 17
10.2.3 Clear .................................................................................................................................... 17
11 CHECKWEIGHER OPERATING MODE:........................................................ 17
11.1 Determination of the weight: .......................................................................................................... 18
11.2 Providing the result value : ............................................................................................................ 19
11.2.1 Outputs synchronization:..................................................................................................... 19
11.2.2 With the SCMBus protocol: ................................................................................................. 19
11.2.3 With the ModBus protocol: .................................................................................................. 19
11.2.4 With the CANopen® protocol: ............................................................................................. 19
11.3 Management of Set-points:............................................................................................................ 19
11.4 Dynamic zero ................................................................................................................................. 20
11.5 Checkweigher zero automatic correction ...................................................................................... 20
12 PEAK CONTROL OPERATING MODE:......................................................... 21
12.1 Non-triggered operating mode:...................................................................................................... 21
12.2 Triggered operating mode: ............................................................................................................ 21
12.3 Management of Set-points:............................................................................................................ 22
12.4 Other possible outputs assignments:............................................................................................. 22

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Digital Transmitter
eNod3-C: User’s instructions
NU-eNod3C-E-0911_165702-I
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1 GENERAL PRESENTATION:
eNod3-C provides an economic high performance solution to transform any strain gauge sensor
into an intelligent digital system. eNod3-Cincludes three advanced operating modes for control of
static and dynamic processes:
-Measurement transmitter.
-Checkweigher.
-Peak control.
eNod3-Cis provided with RS485/422, RS232 and CANbus outputs supporting the ModBus-RTU,
SCMBus and CANopen® protocols. Each module is provided with 2 logical inputs and 2 logical
outputs, authorizing synchronization of functions with automation and alarm management.
SCAIME provides the eNodView software to facilitate installation of eNod3-Cto set parameters
and calibrate the measurement system, for acquisition of measurements and simulation of digital
filters.
1.1 Dimensions:
With waterproof housing version a connecting cable with a shield grounded on both sides should
be used to connect peripheral devices and eNod3.
Cable gland is provided with an inside contact spring for an easy and safe EMC connection of
shield cable and housing.
Single board card Waterproof
housing version
DIN rail version

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Digital Transmitter
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1.2 General characteristics:
Power supply Unit
power supply voltage 10 ..... 28 VDC
max consumption 70 with 350Ωload cell
120 with 80Ωload cell mA
Temperature range
storage temperature -25...+85 °C
operating temperature -10...+40 °C
Load cell
impedance (complete bridge) > 80 Ω
connection 4 or 6 wires
load cell power supply 5 ± 5% VDC
Communication
RS232
RS 485/422 Half or full-duplex
RS baud rate 9600 ... 115200 bauds
Can 2.0A 20....1000 kbauds
Logical inputs
number 2
type optocoupler
low-level voltage 0 ..... 3 VDC
high-level voltage 9 .... 28 VDC
current at high level 10mA @ 24V mA
insulation voltage 2500 Vrms
Logical outputs
number 2
type opto-insulated static relays
max current @ 40°C 0.4 A
max voltage in open state 55 V
resistance in ON state 2 Ω
insulation voltage 2500 Vrms
Metrological characteristics
analog input signal range 7.8 ... 500 mV/V
typical temperature offset drift @ input
signal range <7,8 mV/V 1.5 ppm/°C
typical slope temperature effect 2 ppm/°C
max linearity error 0.003 %
A/D conversion rate 1920 .... 6.25 meas./s
Legal for use metrological characteristics
Class III or IIII
Maximum number of verification scale
divisions
6000 for class III
1000 for class IIII
Minimum voltage division per verification
scale division (∆Umin) 0.5 µV
Maximum voltage for weighing range 39 mV
Minimum impedance for the load-cell 80 Ω
Maximum impedance for the load-cell 1500 Ω
Value of factor Pi0.5

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Digital Transmitter
eNod3-C: User’s instructions
NU-eNod3C-E-0911_165702-I
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Programmable functions
acquisition of zero, taring, zero tracking
physical or theoretical calibration
slope correction
non-linearity polynomial correction
low-pass, band-stop and self-adaptive digital filters
set points management
checkweigher functioning mode
peak detection functioning mode

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Digital Transmitter
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2 INTERFACES:
2.1 Connection to the power supply:
The ‘POWER’ light shows whether or not the power supply is connected.
2.2 Connection to load cell(s):
eNod3-Csupplies power to the load cells (5 VDC).
Up to four 350Ωload cells can be connected in parallel.
eNod3-Callows the use of 4- or 6- wire load cells.
-4-wire load cells: jumpers in place.
-6-wire load cells: jumpers removed.
Power supply
10 to 28VDC PWR+
PWRREF
POWER
_
+
2
1
4/6- wire jumpers
ON : 4 wires
OFF : 6 wires
Exc+
Sens+
Exc-
Sens-
Sig+
Sig-
Shield
1
2
3
4
5
6
7

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Digital Transmitter
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2.3 Connection of Inputs & Outputs:
2.3.1 Digital inputs
connection to a detector :
connection to a push button (PB) :
2.3.2 Digital outputs
Output characteristics (opto-insulated static relays)
Max current @ 40°C 0.4A
Max voltage in the open state 55V
Resistance in the ON state 2 Ω
Insulation voltage 2500 Vrms
A light is assigned to each output.
Characteristics of opto-insulated Inputs
High level 9 - 28VDC consumption 10mA @ 24VDC
Low level 0 to 3 VDC
NC
NC
OUT 2
OUT 1
OUTCOM
IN 2 –
IN 2 +
IN 1 –
IN 1 +
1
8
9
7
6
5
4
3
2

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Digital Transmitter
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2.4 COMMUNICATION INTERFACES:
eNod3-Cis capable of communicating with an automatic control for each connection:
The connection to the RS 485 / RS 422 interface is made through TA, TB and RA, RB connections on the 9-
pins connector. (TA = direct transmission, TB = inverse transmission, RA = direct reception, RB = inverse
reception).
For an RS485 (half duplex) communication, just connect the TB and TA pins and remove the corresponding
jumper (OFF).
For an RS422 or RS485 full-duplex communication, use the four TB, TA, RB and RA pins. The corresponding
jumper must be in place (ON) (which is the default case on delivery).
The RS232 interface is connected using Tx, Rx and REF connections on the 9-pin connector.
The CAN interface is connected using the CANH, CANL and REF (not mandatory) connections on the 9-pin
connector.
3 COMMUNICATION:
jumper CAN/RS ON
-RS485/422
-RS232
-CAN jumper CAN/RS OFF
+
-
55 VDC max
OUTCOM
OUT
Load
+
-
55 VDC max
OUTCOM
OUT
Load
OUTCOM
OUT
Load
38 VAC max
RS485 jumper
ON : Full duplex
OFF : Half duplex
CAN / RS jumper
ON : RS
OFF : CAN
TB
TA
RB
RA
Rx
TX
REF
CANL
CANH
RS232 CAN
RS485
Half/Full
communication
9
7
6
5
4
3
2
1
8

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Digital Transmitter
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eNod3-Ccan communicate using several protocols:
- ModBus RTU
- SCMBus standard format or fast format.
- CANopen®
Switching from the SCMBus protocol to the ModBus-RTU protocol (and reciprocally) can be
done by software programmation.
1) send the corresponding command
2) send the ‘storage in EEPROM’ command
3) reset (hardware or software)the device
See example describing how to switch from ModBus-RTU to SCMBus protocol in the
document SCMBUS communication Ref 165 706 Appendix A.
Switching from SCMBus/ModBus-RTU protocol to CANopen® protocol (and reciprocally)
can be done by setting or removing the appropriate jumper (cf. §3) then by making a reset
3.1 ModBus RTU:
See the description of the frames and functions in the ‘ModBus RTU communication protocol’ Ref.
165 704 document.
3.2 SCMBus:
See the description of the frames and functions in the ‘SCMBus communication protocol’ Ref.
165 706 document.
The SCMBus protocol has got similarities with ModBus-RTU. It is based on the master/slave
structure however it allows to transmit measurements continuously without collision management
on the line. This operating mode is only available in transmitter functioning mode.
The measurements transmission frequency depends on the serial baud rate thus transmitting 100
meas/s is impossible at less than 19200 bauds. For fast measurement transmissions, use the fast
SCMBus format with wich 1200 meas/s can be expected at 115200 bauds.
Other methods of transmitting information without any master request :
-transmitter mode : measurement transmission triggered by a digital input.
-whatever the functioning mode is, physical calibration procedure : automatic
transmission when a step in the process is complete.
3.2.1 Fast SCMBus format:
The Fast SCMBus format is particularly useful for measurement acquisitions at the highest
frequency, for example, in order to analyse dynamic phenomena.
This format should only be used for point-to-point operation in full-duplex.
To optimize the speed, in addition to using the Fast SCMBus format, it is preferable to configure
eNod3-Cfor operation with ‘no processing transmitter’. In this configuration, filters are inactive, set-
points are not managed and there is no polynomial linearization.
3.3 CANopen®
eNod3-Csupports CANopen® communication protocol and is compliant with ‘CIA® Standard
V301’. See the description of the frames and functions in the ‘CANopen® communication protocol’
Ref. 165 717 document.

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Digital Transmitter
eNod3-C: User’s instructions
NU-eNod3C-E-0911_165702-I
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4 USE IN LEGAL FOR TRADE APPLICATIONS :
4.1 Introduction
eNod3-is a module making a part of an instrument. It is intended to be integrated :
-In a non automatic weighing instrument (NAWI) or
-In an automatic weighing instrument (AWI) of category catchweigher.
4.2 Legal for trade parameters
See relative sections in the following documents :
-ModBus RTU communication Ref. 165704
§ 2.11 Metrological version number
§ 2.12 Legal for trade
§ 2.37 Status register
-SCMBus communication ref. 165706
§ 4.3 Legal for trade settings
§ 1.4 Status bytes
-CANOpen® communication protocol Ref. 165708
§ 3.2.16 Legal for trade switch
§ 3.2.17 Legal for trade indicators
§ 3.2.32 Current measurement
§ 3.2.33 Current measurement status
4.3 Sealing
The module eNod3-Chas a physical sealing device and a software sealing device.
4.3.1 Physical sealing :
The physical sealing is the one of the module box. It comprises two self-adhesive stickers self-
destructive when removed or a device with sealing screws with lead and sealing wire.
4.3.2 Software sealing :
On the whole weighing instrument the value of the event counter as well as the CRC value may be
displayed.
The whole weighing instrument has a marking area where the values of the event counter and of
the CRC recorded after the last official verification.These marked values shall be identical to these
displayed on the terminal. When these values do not match, this part of the sealing device is
considered as broken.
4.4 Specific requirements :
The legal metrological software version may be displayed on the terminal.
There are also some characteristics in the status related to measurements that need to be
displayed on the terminal too.
Sealing with self-adhesive stickers self-
destructive when removed put on 2
opposite sides of the box, with a part on
the top and a part on the side of the box.
Sealing with lead and sealing wire, 2
opposite screws have to be sealed.

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Digital Transmitter
eNod3-C: User’s instructions
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5 CALIBRATION
5.1 Calibration types:
There are different possible calibration types (See examples in the documents: ‘SCMBus
Communication’ Ref. 165 706 Appendix A and ‘ModBus RTU Communication’ Ref. 165 704
Appendix A):
- Physical calibration using the load cell through a known reference. This type of calibration
can be done with 1, 2 or 3 known references.
- Theoretical adjustment by setting the load cell sensitivity and capacity.
- Correction of the initial calibration value.
5.2 Linearization correction:
For an installation with a non-linearity:
The linearization formula is as follows:
The coefficients A, B and C are defined using the eNodView software calculation tool.
Corrected measurement = Meas – A (Meas)
2
– B(Meas) – C
where Meas = Current measurement
Linearization of the
measurement / Weight curve
Measurement
Weight
Theoretical
linear
measurement
Non-linear
measurement
Fig. 1

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Digital Transmitter
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6 INPUTS FUNCTIONING:
Each input can function in positive or negative logic individually. A debounce time common to both
inputs can be adjusted.
6.1 Assignment of inputs:
Function Operating mode
Transmitter Checkweigher Peak control
none ●●●
tare ●●●
zero ●●●
transmit
measurement ●
measurement
window ●●
clear ●●●
start cycle ●●
New cycle
allowance ●
stop checkweigher
cycle ●
dynamic zero ●
6.2 General functions:
- none: inputs are inoperative.
- tare : one or the other or both inputs may be assigned to the tare function.
The tare is affected by a stability criterion that can be parameter defined. The tare will be
triggered on a rising or a falling edge, depending on the parameter defined logic (positive or
negative).
- zero: one or the other or both inputs may be assigned to the zero function.
A new zero is only accepted if its value is within a ±10% range of the specified maximum
capacity for a usage out of legal for trade and ±2% for legal for trade application. This zero
value is the current zero value, and is cancelled following a reset. Stability and starting on a
rising or falling edge (same as for tare control).
6.3 Functions attached to an operating mode:
See corresponding sections.

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7 OUTPUTS FUNCTIONING:
Each output can function in positive or negative logic individually.
7.1 Assignment of outputs:
Function Operating mode
Transmitter Checkweigher Peak control
set point ●●●
motion ●●●
defective
measurement ●●●
checkweigher result
available ●
cycle in progress ●●
inputs image ●●●
level on request ●●●
7.2 General functions:
- set point: outputs can be assigned to copying the state of set points. Output 1 is assigned to set
point 1 and output 2 to set point 2.
-motion: outputs can be assigned to copying measurement stability.
-defective measurement: outputs can be assigned to copying measurement faults. These faults
are also coded in the status word attached to the measurements. There are 4 of them:
∗outside converter range on the positive side.
∗outside converter range on the negative side.
∗outside capacity on the positive side.
∗outside capacity on the negative side.
- inputs image: outputs can be assigned to copying inputs, either using the same logic or inverting
the state of the input (negative logic). Output 1 is assigned to input 1 and output 2 to input 2.
- level on request: outputs state is driven by master requests on the communication bus. The
activation duration can be modified.
7.3 Functions attached to an operating mode:
See corresponding sections for a complete description

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8 SET POINTS:
Set points are characterized by a high value and a low value. The operating mode is either
operation in hysteresis, or operation in window.
The values of these set points may be assigned either to:
-gross measurement regardless of the functionning mode
-net measurement regardless of the functionning mode
-maximum value in peak control mode
-minimum value in peak control mode
-peak-to-peak value in peak control mode
-result in checkweigher mode
-running total in checkweigher mode
Functioning in hysteresis
Fig. 2
high
val.
t
output
low
val.
Functioning in window
Fig. 3
high
val.
t
output
low
val.

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Digital Transmitter
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9 FILTERS:
There are four available filtering levels:
∗filtering related to the A/D conversion rate including rejection of the mains frequency
(50 or 60 Hz) harmonics.
∗2
nd, 3rd or 4th order low-pass Bessel/Butterworth filter
∗2
nd order band-stop filter
∗self-adaptive filter
- Filtering related to the A/D conversion rate : the signal resolution is related to the conversion
rate. The conversion rate might be choosen as low as possible, particularly for static applications.
For dynamic applications, a compromise must be found between the measurement rate and the
low-pass filter cut-off frequency. The eNodView software can be used to determine appropriate
filter values.
Choose a measurement rate that rejects the mains frequency harmonics according to the place of
use, 50 or 60Hz.
-Bessel or Butterworth type low pass filter : a low-pass digital filter can be applied as an output
of the A/D converter. The filter order is configurable (available values are 2, 3 or 4) and the
coefficients that define it depend on the A/D conversion rate, the wanted cutt-off frequency and on
the choosen order. These coefficients can be easily calculated by eNodView software.
- Band-stop filter : a 2nd order band-stop filter might be applied as an output of the low-pass filter
(if used) or the A/D converter. It allows to attenuate the frequencies within a band defined by a high
and a low cut-off frequencies. The coefficients that define it depend on the A/D conversion rate and
the wanted cutt-off frequencies (that means the frequency band width). These coefficients can be
easily calculated by eNodView software.
- Self-adaptive filter : this filter can be set in cascade after previous filters. It is particularly efficient
for static measurements but avoid using it in dynamic or dosing processes. The aim of this filter is
to eliminate erratic measurements and to average consistent measurements.

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10 TRANSMITTER OPERATING MODE:
This basic operating mode consists of transmitting measurements on the bus, possibly after
configuring them, filtering them and comparing them with set-points levels.
Measurements can be transmitted individually regardless of the communication protocol or
continuously at a defined period in the SCMBus (standard or fast format) and CANopen®
protocols. Functioning may be unipolar (positive analog signal only) or bipolar (positive or negative
analog signal).
10.1 Measurement reading request:
10.1.1 Single measurement transmission:
Regardless of the communication protocol in use.
The request can apply to:
-gross measurement.
-net measurement.
-tare value.
-measurement in A/D converter points.
10.1.2 Continuous measurement transmission:
This is possible using standard or fast SCMBus format, the transmission can be started by a
serial command and another one allows stopping it. Measurements are transmitted at a period
defined in ms by the ‘sampling period’ setting.
The request can apply to:
-gross measurement.
-net measurement.
-measurement in A/D converter points.
Note: This is very similar to operation of the ‘Measurement window’ through an input command.
CANopen® protocol also allows defining a period at which measurements are sent on the bus
without any master request.
10.2 Specific commands through an input:
10.2.1 Transmit measurement (fig. 4)
This is only possible using standard or fast SCMBus format or
CANopen® protocols.
The request can apply to:
-gross measurement.
-net measurement.
-measurement in A/D converter points.
A single measurement is transmitted per rising or falling edge
(depending on the configured logic) on the input signal.
10.2.2 Measurement window (fig.5)
This is only possible using standard or fast SCMBus.
The request can apply to :
-gross measurement.
-net measurement.
-measurement in A/D counts.
While the input is kept at the right level, a series of measurements
are transmitted at the period defined by the ‘sampling period’
setting.Only input 2 is operational if both inputs are assigned to
this function.
10.2.3 Clear
Cancels current tare (same functioning as ‘cancel tare’ command).
11 CHECKWEIGHER OPERATING MODE:
Load
t
inpu
t
Measur.
Fig. 4
Fig. 5
Load
t
inpu
t
output
period
Measur.

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This operating mode consists of determining the weight of an object while it is present on a
conveyor portion on which a weighing system is fitted (Fig 6).
Note: The measurement is determined for net measurements only.
11.1 Determination of the weight:
When the object arrives on the weighing system, the weight determination cycle can be started:
- by an input assigned to ‘start checkweigher cycle’ (Fig. 7 & 8).
Caution, only input 2 is operational if both inputs are assigned to the ‘start
checkweigher cycle’ function.
- by a trigger level (Fig. 9) when the load cell signal reaches the specified value.
Then, during a ‘stabilization time (Ts)’, the signal is highly disturbed so measurements are not
taken into account. Finally, during a ‘measuring time (Tm)’ defined by either:
- a time value (Fig.7).
Time
Load cell signal
Communication
Fig. 6
Fig. 8
t
Stab.
time
I - Start cycle
I - End cycle
Load
Resul
t
available
t
Stab.
time Measuring
time
I - Start cycle
O - Cycle in process
Load
Result
available
Fig. 7
Fig. 9
Set poin
t
high
t
trigge
r
level
Set poin
t
lo
w
Stabilisation
time Measuring
time
Resul
t
available
O - Set
p
oint
O - Result available
Load

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- a duration prior to an edge on an input assigned to ‘stop checkweigher cycle’
(Fig.8).
Caution, only input 2 is operational if both inputs are assigned to the ‘stop
checkweigher cycle’ function.
eNod3-Cautomatically 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
eNodView can be used to determine stabilization and measurement times so as to optimize
parameters. (See eNodView user’s instructions documentation).
11.2 Providing the result value :
11.2.1 Outputs synchronization:
Two specific functions may be assigned to eNod3-Clogical 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).

eNod3-C
Digital Transmitter
eNod3-C: User’s instructions
NU-eNod3C-E-0911_165702-I
20/22
11.4 Dynamic zero
If an input assigned to the ‘dynamic zero’ function is activated or if a ‘dynamic zero’ command is
received, eNod3-Ccalculates the measurement average value during a configurable time. This
value becomes effective if it is within a ± 10% range of the specified maximum capacity or ±2% in
legal for trade application. Stability is not required.
11.5 Checkweigher zero automatic correction
eNod3-Calso provides an automatic zero tracking for dynamic applications. It allows to follow the
evolution of the zero in checkweigher functioning mode, for example on a conveyor belt on which
there is some product accumulation
This function is efficient only when the measured signal is filtered enough with few noise and
oscillations.
When this function is enabled, an average value is calculated if comprised within a configurable
interval around the zero calibration and during a configurable period. Some other criteria are also
taken in account, they are:
- Number of measurements complying with correction range compared with
total number of measurements received during dynamic acquisition time, it
must be > 75%.
- At least 10 measurements included in the interval are necessary.
In legal for trade application:
- The interval cannot exceed ±5d
- The dynamic acquisition time is 1 second minimum
- Checkweigher zero automatic correction is disabled if measurements are
stable.
Recommendations:
- To avoid undesired zero correction, preferably set zero automatic correction
only when weighing belt is in use.
- Dynamic acquisition time should be higher or equal to checkweigher
measuring time.
- Dynamic acquisition time should be lower than free time between two
measurements.
- Interval of the zero automatic correction should be lower than checkweigher
trigger level.
- Interval of the zero automatic correction should be in correspondence with the
variation interval due to mechanical motion. The value should be lower than
10d.