WOBIT MD150T User manual

P.P.H. WObit E.J.K. s.c.
Dęborzyce 16, 62-045 Pniewy
tel.[phone], fax.[phone]
e-mail: [email protected] www.wobit.com.pl
MD150T
Manual
Digital processing unit with display for
force sensors without amplifiers

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Manual -MD150T –27.10.2014 –v.1.3
page 2
Contains
1. Safety and assembly rules.............................................................................. 3
2. Device description ......................................................................................... 4
2.1 Intended use and properties ..................................................................... 4
2.2 Description of connectors and front panel.................................................. 5
2.3 Force sensor connection ........................................................................... 5
3. Menu description ........................................................................................... 7
3.1 MENU map .............................................................................................. 7
3.2 Example of parameter change .................................................................. 8
4. Configuration of measurements ...................................................................... 8
4.1 Configuration of force sensor .................................................................... 8
4.2 Reset of sensor indications ....................................................................... 8
4.3 Filtering of measurements ........................................................................ 9
4.4 Units of measurement .............................................................................. 9
5. Configuration of relay outputs ........................................................................ 9
6. Password protection .................................................................................... 10
8. USB and RS485 MODBUS interfaces.............................................................. 11
8.1 USB interface......................................................................................... 11
8.2 RS485 (MODBUS-RTU) interface ............................................................. 11
8.2.1 Description of MODBUS protocol ....................................................... 11
9. Complementary information ......................................................................... 13
9.1 Type of force sensors ............................................................................. 13
9.2 Measuring range of sensor...................................................................... 13
10. Technical parameters ................................................................................ 14
Thank you for selecting our product!
This instruction will help you at correct service and accurate exploitation of described device.
Information included in this instruction were prepared with high attention by our specialists and is description of the
product without any responsibilities within the meaning of the commercial law. Based on the information should not be
inferred a certain features or suitability for a particular application. This information does not release the user from the
obligation of own judgment and verification. P.P.H. WObit E.K.J. Ober s.c. reserves the right to make changes without prior
notice.
Please read instructions below carefully and adhere to its recommendation
Please pay special attention to the following characters:
CAUTION!
Not adhere to instruction can cause damage or impede the use of hardware or software.

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Manual -MD150T –27.10.2014 –v.1.3
page 3
1. Safety and assembly rules
Safety rules
•Prior to first start-up of the device carefully read the manual.
•Prior to first start-up of the device make sure all cables are properly connected.
•Provide appropriate working conditions, in compliance with the device
specifications (e.g.: power supply voltage, temperature, maximum current
consumption).
•Prior to any modifications of cables connections, disconnect power supply voltage.
•Dismantling of the indicator housing during guarantee agreement period results in its
invalidation.
Assembly recommendation
In the environments of unknown levels of interruptions it is recommended to use the following
means preventing against possible interruptions of the device operation:
•Ground or zero the metal rails on which instruments are mounted.
•Do not power the device from the same lines as high power devices without appropriate
network filters.
•Apply power supply, sensor and signal cables screening while screen grounding should be
connected only on one side as close to the device as possible.
•Use communication cables (USB) equipped with filters in the form of ferrite beads.
•Avoid routing control (signal) cables in parallel with or in close vicinity of power and supply
cables.
•Avoid close vicinity of devices generating high level of electromagnetic and/or pulse
interference (high power loads, loads with phase or group power regulation).

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Manual -MD150T –27.10.2014 –v.1.3
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2.Device description
2.1 Intended use and properties
MD150T is an universal processing display indented to measurement signals from load cell force
sensors. Built-in analog-digital transducer allows for measurement with resolution up to 100.000 of
measuring range. The measurement result is presented on six position display.
MD150T has multipurpose usage as well at industry as in laboratory, where averaged or precise force
(weight) measurement is necessary. Depends on used sensor there is a possibility of small masses in
range as well small weights (grams) as large loads (tons).
MD150T has 2 relay outputs, and 2 dedicated inputs (one tare input). Built-in operating modes
enable the device to be used for dosing without any need for additionally controllers.
MD150T is also equipped with USB and RS485 MODBUS interfaces. USB interface allows fast
configuration and recording measurement data in PC (e.g. to Excel file) with the use of MD150-PC
software. MODBUS-RTU allows for reading of measurements from several indicators at the same
time to PLC controller, HMI panel or its own PC application.
One-level menu of the device is easy in use, and to configure the device for specified sensor is
needed only setting two parameters: constant bridge sensitivity (mV/V) and bridge range (N). User
can also select units of displayed result.
MD150T has full aluminium profile housing compliant with DIN43700 standard which guarantees
high mechanical durability and resistance to adverse environmental conditions including electric
interference.
MD150T features:
Result conversion to N, kN, g ,kg, T, Funt,
Digital filtering and average of
measurements,
Changes of status of relay outputs
based on set thresholds.
Memory of minimal and maximal value,
External tare input,
Cooperation with MD150T-PC software
(communication by USB) for configuration
and visualization of measurements,
RS485 MODBUS-RTU interface,
Solid, aluminum housing.
Picture. 1 Example of MD150T external connections.

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2.2 Description of connectors and front panel
Front panel
LED1
- indicator of PK1 relay activation
LED2
- indicator of PK2 relay activation
ESC
- abortion, Reset
DOWN
- next menu position/next parameter digit
UP
- previous menu position / digit value increase
ENTER
- menu entry/confirmation of entered changes
Back panel
1
E+
Power supply+ sensor (Excitatnion+)
2
S+
Signal+ sensor (Signal+)
3
S-
Signal- sensor(Signal-)
4
E-
Power supply- sensor (Excitatnion-)
5
TARA
Tare input (+5..+24V)
6
DIN2
Universal input
7
485A
A Signal of RS485 interface
8
485B
B Signal of RS485 interface
9,10
PK1
PK1 (NO) relay contacts
11,12
PK2
PK2 (NO) relay contacts
13
V+
12-36 VDC power supply, min. 250mA
14
GND
Power supply mass
2.3 Force sensor connection
MD150T digital processing unit can be integrated with any force sensor, which has input with
resistance of standard bridge bigger than 150Ω. Sensor should be connect according to scheme
below.
Picture. 2 Way of connecting force sensor to MD150T digital processing unit

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Manual -MD150T –27.10.2014 –v.1.3
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Sensor model
Signals
K200, K300, K500,
KB52, KB82, KMB19,
KMB25, KMB31
K701, K801,
K1101, K1506
K1401, K1501,
K1600
KMM20, KMM30, KMM40,
KMM50, KMM60, K1505,
EMS70, EMS150, EMS200
Power supply+
(E+)
Red
Brown
Red
White
Power supply-
(E-)
Black
Yellow
Black
Brown
Signal+ (S+)
Green
Green
Brown
Yellow
Signal- (S-)
White
White
Yellow
Green
Tab. 1 Description of cable colors for force sensors of WObit’s offer.
CAUTION!
In longer period of time can happen, that derivation colors can change. Wrong connection do not
cause damage device or sensor. It only cause indicating of opposite value (at changing E+ form E-
or S+ from S- derivation), or incorrect (exchange between power supply and output).
CAUTION!
Do not short-circuit derivation cables of sensor power supply (E+,E-), and also do not short-circuit
E+ output to other derivation, it can cause damage of the device.

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3.Menu description
3.1 MENU map
000000 -> displaying of current measurement value
Menu entry
- Min. measurement value display
- Max. measurement value display
(3 sec.) Zeroing of min/max
measurement value
1. P1 -> Menu
Next/previous
parameter
parameter selection
Digit selection
Change value
Parameter edition
1.
P1
PK1 relay threshold
Relays
± 999999
2.
P2
PK2 relay threshold
± 999999
3.
P3-H
Relays switching on/off hysteresis
± 999999
4.
MODE
Relays operational mode
mode 0 / 1
5.
TARA
Zeroing of sensor indications
Measurements
6.
OFFS
Offset for measuring value
± 999999
7.
UNIT
Units
N, kN, g, kg, T, funt
8.
RATE
Measurement frequency
10 Hz / 80 Hz
9.
FILT
Level of averaging continuous filter
0…99
10.
TRA
Bridge range [N] configuration parameter
0..999999
11.
TSE
Bridge constant [mV/V] configuration parameter
0..99.9999
12.
DP
Number of decimals of the result
0..3
13.
ADR
MODBUS address
RS485
0-99
14.
BAUD
MODBUS baud rate
9600 / 19200 / 38400
57600 / 115200
15.
BEP
Keys audible signal
Other
On / OFF
16.
LED
Display brightness level
0-9
17.
FAC
Restoring factory default settings
18.
PAS
Password
X-0000 - not active
Menu exit/abortion
Parameter confirmation/abortion
Blinking measurement value means exceeding of sensor rated load (more information- chapter
Błąd! Nie można odnaleźć źródła odwołania.).

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3.2 Example of parameter change
After correct connection of external elements and switching power supply on, MD150T process
display is ready for operation with previously used settings, and in case of first operation –with
factory settings.
In order to enter programming mode, press . The display shows 1. P1, if the password is
switched off or 0000, if it is active . In such case, in order to enter programming mode (at
active password) enter the password and confirm it with the key ;
•With subsequent pressing of key you switch to next parameters and with pressing of
key you return to previous parameters.
•At the selected parameter you want to change, press ;
With key select display digit position you want to change and change its value with key
. Confirm the entered value with key ;
Value of single digit parameters is selected with keys and ;
•If you want to enter a negative value select the first digit (from the left) then press and hold
key until the symbol “-“ is displayed.
With key you confirm the introduced change and with key you abort the change or
exit the menu.
Prolonged pressing of keys or results in automatic increase/decrease of a given
position/value.
4.Configuration of measurements
4.1 Configuration of force sensor
MD150T for correct displaying value from load cell requires giving of two parameters:
Parameter 10. TRA –bridge range. Rated load of used sensor in N (1 –999999), usually given
on sensor casing,
Parameter 11. TSE –bridge constant –sensitivity of used sensor in mV/V (0.0001 –99),
usually given on sensor casing or in its documentation.
Standard force sensors have constant with range 1 to 2mV/V with given accuracy by manufacturer
(usually 0.05% - 0.5% linearity).
KMMXX sensor series from WObit’s offer are characterized by specified constant for each model,
given with accuracy up to 4 decimals. For example strain gauge bridge KMM20-500N type with given
on causing 6724/06 serial number has 0.9906 constant (value read from bridge documentation).
For example for KMM20-500N sensor with 0,9906 constant MD150T should be configure,
respectively:
To 10. TRA parameter set 500 value
To 11. TSE parameter set 0,9906 value
4.2 Reset of sensor indications
Reset from keyboard: Menu -> 5. TARA -> Confirmation.

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Reset by external signal TARA (clamp nr. 5). Reset signal should has length min. 10ms, and
interval between next reset signals should not be shorter than 0,5 sec.
Picture. 3 Reset of sensor by external signal TARA.
Reset value is remain at non-volatile memory of digital processing unit.
4.3 Filtering of measurements
Parameters 8. RATE and 9.FILT have influence on indications durability.
Parametr 8. RATE specifies measurement frequency(10Hz, 80 Hz). Lower frequency provides
more stabile indications.
Parametr 9. FILT specifies filtration level of digital averaging filter. Higher filtration value
(max. 99) provides more stabile indications, however, response to changes of the measured
signal is slower.
4.4 Units of measurement
Units of measurement are set by 7. UNIT parameter. The user has following units for selection:
1N–Newton’s, 2 kN –kilonewtons, 2 g–grams, 3 kg –kilograms, 4 T–tones, 5 Funt-
pound
Additionally 12. DP parameter specifies number of decimal places of indicated value. When DP will
set on 0 digital processing unit will display only complete part of measurement. For DP = 4 result will
has four decimal places.
Parameter DP influence also on measurement range of set parameters. If DP = 0, then P1, P2, P3-H
settings, could be change only at complete part in range -99999 do 999999. If DP=4 parameters
above could be change in range of -99.9999 up to 99.9999.
5.Configuration of relay outputs
MD150T digital processing unit has 2 relay outputs PK1 and PK2 which can be switched on/off
depending on current measurement value. The following parameters are used for relay outputs
configuration:
1. P1 -activation (deactivation) threshold of PK1 relay
2. P2 -activation (deactivation) threshold of PK2 relay

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3. P3-H - hysteresis level of activation/deactivation of PK1 and PK2 outputs
4. MODE - output operating mode:
Mode 0 –Absolute with two thresholds. Activation of PK1 and PK2 outputs is realized after
reaching of P1 and P2 values, respectively.
Mode 1 –Reverse with two thresholds. Operation is similar to the above mode. Deactivation
of PK1 and PK2 outputs is realized after reaching of P1 and P2 values, respectively.
6.Password protection
Access to the process display settings can be password protected (parameter 11. PAS). There are 3
protection levels available. Protection level is set with the first digit, and the last 4 digits are used for
password entry.
0-0000
4-digit password (0-9999)
Protection level:
0-Settings protection above 12. DP
parameter
1-Settings protection above 3. P3-H
parameter
2-Protection of all settings
If the digital processing unit is password protected, then
after switching to protected settings the display shows
0000 value –enter previously set password. The password
can be deactivated by switching the parameter 18.PAS and
setting 0000 value.
Menu protection level
1. P1
2. P2
3. P3-H
4. MODE
5. TARA
6. OFFS
7. UNIT
8. RATE
9. FILT
10. TRA
11. TSE
12. DP
13. RS1
14. RS2
15. BEP
16. LED
17. FAC
18. PAS
2
1
0
Fig. 2 Example of PK1 relay output activation depending on P1 and P3H setting and operatingl mode (MODE).
Measurement value '
P1+P3H P1
P1-P3H
PK1 relay status
(MODE=0)
PK1 relay status
(MODE=1)

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7.USB and RS485 MODBUS interfaces
7.1 USB interface
USB interface is used for communication of MD150T process display with MD150-PC software (device
configuration, recording of measurements) and for updating of internal software. MD150 process
display must be powered in order to facilitate communication via USB.
Caution!
USB interface is prone to interference in the power supply grid and to electromagnetic
interference occurring in industrial environments. In case of connection problems during
communication of the digital processing unit with MD150T-PC software, apply additional
protective elements in the form of:
Powering of MD150T digital processing unit from an independent power supply source,
Application of network filters upstream of the indicator supply feeder.
Use of USB cable of length <1,5m equipped with ferrite beads at the cable beginning and its end.
Use of optically insulated USB hubs at PC side.
In the conditions of severe interference (e.g. high interference of power grid) the communication may not
be possible.
7.2 RS485 (MODBUS-RTU) interface
MD150T digital processing unit is equipped with RS485 interface. It can be used for communication
with PLC controller, HMI panel or other device supporting MODBUS-RTU protocol. Default
transmission parameters:
Speed: 38400bps, Bits: 8, Stop Bits: 1, parity: none
Address Modbus: 1
Transmission speed and MD150T digital processing unit address in MODBUS-RTU network can be set
with the following parameters:
13. ADR - speed setting MODBUS (9600, 19200, 38400, 57600, 115200)
14. BAUD - address setting MODBUS (1…99)
7.2.1 Description of MODBUS protocol
Implemented functions MODBUS
Function no(hex)
Description
1 (0x01)
Reading of outputs status (relays)
3 (0x03)
Reading X registers
5 (0x05)
Recording of single Bit
Type of variables used
Name
Description
Size
(Bytes)
Number of occupied registers
DINT
Complete number with a
sign
4
2
REAL
Floating point number
4
2

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Map of MD150T records
Address
Name
Variable type
Mode(Modbus
function)
Description
0 -1 (*1-2)
MES_DINT
DINT
R (0x03)
Measurement value (only complete part)
2 -3 (*3-4)
MES_MIN_DINT
DINT
R (0x03)
Registered minimal value (only complete
part)
4 -5 (*5-6)
MES_MAX_DINT
DINT
R (0x03)
Registered maximal value (only complete
part)
6 -7 (*7-8)
MES_REAL
REAL
R (0x03)
Measurement value (floating point)
8 -9 (*9-10)
MES_MIN_REAL
REAL
R (0x03)
Registered minimal value (floating point)
10 -11 (*11-12)
MES_MAX_REAL
REAL
R (0x03)
Registered maximal value (floating point)
5000 (*5001)
TARA
BYTE
W (0x05)
Reset of sensor indications.
5002 (*5003)
PK_OUT
BYTE
R (0x01)
Reading of relay outputs status
(bit 0:PK1, bit 1:PK2)
4000 (*4001)
INPUTS
BYTE
R (0x01)
Reading of inputs status
(bit 0: TARA. bit 1: DIN2)
*for devices with address starting with 1 value(offset address +1)
R –reading register, W - record
CAUTION: 4-Byte number of type REAL is contained in two registries. The first registry contains younger part of the number,
the second - its older part. In order to read REAL number value correctly, read registries of number 2 and 3 and then
conduct appropriate conversion.
Conversion of 2 registries (4 Byte) into 32 Bit number REAL
Registry_2 HI <-> Byte1
Registry_2 LO <-> Byte0
Registry_3 HI <-> Byte3
Registry_3 LO <-> Byte2
Number _32_bit = Byte3<<24 + Byte2<<16 + Byte1<<8 + Byte0
Or number_32_bit = Registry_2 + Registry_3<<16
For DINT registers, if measurement result is within range -32768 up to 32767 reading of first register
is enough.
Example of MODBUS communication table
Reading of measurement (DINT value) –MES_DINT (Function: 03, Registry address: 0)
Request (MODBUS MASTER -> MD150T)
Response (MD150T -> MODBUS MASTER)
Device address
0x01
Device address
0x01
Function
0x03
Function
0x03
Hi registry address
0x00
Byte number
0x04
Lo registry address
0x00
Registry 0x02 Hi
REAL (Byte1)
Number of Hi registries
0x00
Registry 0x02 Lo
REAL (Byte 0)
Number of Lo registries
0x02
Registry 0x03 Hi
REAL ( Byte 3)
CRC Hi
0xC4
Registry 0x03 Lo
REAL (Byte 2)
CRC Lo
0x0B
CRC Hi
8 bit
CRC Lo
8 bit
Reset of digital processing unit - TARA (Function: 05, Registry address: 5000)
Request (MODBUS MASTER -> MD150T)
Response (MD150T) -> MODBUS MASTER)
Device address
0x01
Device address
0x01
Function
0x05
Function
0x05
Address of Hi registries
0x13
Address of Hi registries
0x13
Address of Lo registries
0x88
Address of Lo registries
0x88
Registry 0x00 Hi
0xFF
Registry0x00 Hi
0xFF
Registry 0x00 Lo
0x00
Registry0x00 Lo
0x00
CRC
16 Bytes
CRC
16 Bytes

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8.Complementary information
8.1 Type of force sensors
WObit company has a broad offer of force sensors in range from single Newton’s up to hundreds of
kilonewtons. Depends on assembly and way of measuring force (tension, compression) are available
sensors with different shapes (table below).
Beam
To measure tension force. Range of measured force 0..350N.
Example of models: K200, K300
S-beam
To measure large tension force. Range of measured force 0..75kN.
Example of models: K1401, K1501, K1505, K1506, K1600
Round
To measure large and small tension force. Range of measured force
0..100kN.
Example of models: KB52, KB82, KMB19, KMB25, KMB31, KMM30,
KMM50, KMM60,
Round with shaft
To measure large and small tension and compression force. Range of
measured force 0..50kN.
Example of models: KMM20, KMM40
Cylindrical
To measure large tension and compression force. Range of measured
force 0..200kN.
Example of models: K1101
8.2 Measuring range of sensor
Destroying load
>200% TRA
Cut-off load
+200% TRA
Applied load
+150% TRA
Rated load
+100%
TRA
Measuring range
Zero load
0 [N]
Rated load
-100%
TRA

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Rated load for sensor it is a size of force, which specifies
top value of measuring range (given value for sensor as
bridge range -TRA in N).
Applied load is the biggest force, which have
unambiguous connection between force and output
signal (signal value is changing linear in relation to force). It can count max. M150% of sensor range
(bridge).
Cut-off load is the biggest force, which can Take each sensor without it damage. It can count max.
200% of sensor range.
Destroying load means force applied to sensor Shaft, which exceeding can cause to mechanical
damage of the sensor.
Constant of e.g. KMM60 sensor is 1,5mV/V 2%. Error of the sensor is specified by following values:
tolerance of linearity 0,2% of measuring range, zero tolerance 2% of measuring range, hysteresis
0,2% of range and creep measured in time of 30 minutes 0,1%. Temperature factor of zero point
and constant is 0,1% of range/10oC. Bridge resistance on input has 380om ±10% and output
resistance has 350om ±5%.
9.Technical parameters
Description
Parameter
Power supply
12 … 36 VDC, 250mA
Sensor input
Sensor power supply: 5V
Max. differential voltage: ±39mV,
Resolution: 0,001% FS,
Temperature error: 0,0025%/C°
Frequency of measurements: 10Hz, 80Hz
Zeroing input TARA
Low level: 0V (max. 2V), high level: +24V (5…24V)
Minimal pulse length >10ms, minimal pause. 0,5sek.
Relay outputs PK1, PK2
2 x 1A/125VAC, 2A/30VDC
Interfaces
RS485 MODBUS-RTU,default parameters 38400bps, 8:n:1,
USB: 1.1, 2.0
Operating temperature range
0..50o C
Display
6 digits, height13.5 mm
Housing
height: 45 mm
width: 92 mm
length: 81 mm
Weight
200g
Degree of protection
IP40, from panel head –IP65
Universal password
3145
Applied load
-150% TRA
Cut-off load
-200% TRA
Destroying load
<200% TRA