WOBIT MD150A 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
MD150A
Manual
Digital process display 0-10V, 4-20mA
Programmable indicator for sensors with current, voltage or
potentiometer output

www.wobit.com.pl
Manual -MD150A –27.10.2014 –v.1.2
page 2
Table of content
1. Safety and assembly rules.................................................................................................. 3
2. Device description.............................................................................................................. 4
2.1 Intended use and properties ....................................................................................... 4
2.2 Description of interfaces and front panel ................................................................... 5
2.3 Connections diagram................................................................................................... 5
3. Menu description ............................................................................................................... 6
3.1 MENU map................................................................................................................... 6
3.2 Example of parameter change .................................................................................... 7
4Configuration of measurements ........................................................................................ 7
4.1 Configuration of 0-10V / 0-20mA input....................................................................... 7
4.2 Configuration of measurement units .......................................................................... 7
4.3 Number of decimals of the result/parameters ........................................................... 8
4.4 Filtering of measurements .......................................................................................... 8
5. Configuration of relay output ............................................................................................ 8
6. Digital input DIN1, DIN2 ..................................................................................................... 9
7. Password protection .......................................................................................................... 9
8. USB and RS485 MODBUSR interface................................................................................ 10
8.1 USB interface ............................................................................................................. 10
8.2 RS485 (MODBUS-RTU) Interface ............................................................................... 10
8.2.1 Descriptions of MODBUS protocol..................................................................... 10
9. Technical parameters....................................................................................................... 12
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.

www.wobit.com.pl
Manual -MD150A –27.10.2014 –v.1.2
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).

www.wobit.com.pl
Manual -MD150A –27.10.2014 –v.1.2
page 4
2.Device description
2.1 Intended use and properties
MD150A process display is intended for measurement of voltages 0...10V or 0...20mA currents. It
can cooperate with various sensors providing analogue voltage or current output signal and convert
the measurement into a specific unit. Additional 5V voltage output allows for sensor power supply or
connection of potentiometer sensor.
The measurement is realized based on digital converter which can measure the voltage of 1mV
resolution which provides 10000 measurement steps for the range of 0-10V. The measurement
result is presented on six position display.
Apart from measurement output MD150A has 2 relay outputs which can be freely configured for
switching on/off at specified thresholds. The device is also equipped with universal digital inputs
which can be used for external triggering of measurements and for “pausing” of a current
measurement.
MD150A process display is operated intuitively. Configuration for operation with a given sensor does
not require any calculations and it is based on input of output signal range from the sensor and the
range of value displayed on the process display. The process display converts measurement value so
it can e.g. after connection of distance sensor with 4-20mA output it indicates the value in mm.
MD150A is equipped with USB and RS485 MODBUS interfaces. USB interface allows for recording
measurement data in PC (e.g. to Excel file) with the use of MD150A-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.
MD150A has full aluminium profile housing compliant with DIN43700 standard which guarantees
high mechanical durability and resistance to adverse environmental conditions including electric
interference..
MD150A realizes the following functions:
Measurement of voltage or current with resolution of 10000 measurement steps (1mV),
Filtering of signal.
Conversion of voltage/current to any units.
Changes of status of relay outputs based on set thresholds.
Transfer of measurement data to PC (USB) or master device e.g. HMI panel, PLC
controller (RS485 MODBUS-RTU)

www.wobit.com.pl
Manual -MD150A –27.10.2014 –v.1.2
page 5
2.2 Description of interfaces and 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
Panel tylni
1
VOUT
12VDC output, max. 200mA
2
AIN
Analogue input 0-10V / 0 -20mA
4
GND
Ground
5
DIN1
Digital input (5-24V)of measurement
triggering
6
DIN2
Digital input (5-24V) of current value
withholding
7
485A
Signal A of RS485 interface
8
485B
Signal B 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 ground
2.3 Connections diagram
Fig. 1 Example of connections of external signals to MD150A.

www.wobit.com.pl
Manual -MD150A –27.10.2014 –v.1.2
page 6
3.Menu description
3.1 MENU map
4. 000000 -> Displaying of current measurement value
Menu entry
Min. measurement value
display
Max. measurement
value display
(3 sec.) Reset 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.
P3H
Relays switching on/off hysteresis
± 999999
4.
MODE
Relays operational mode
0 / 1 / 2
5.
INPUT
Measurement input mode
Measurement
0..10V / 0..20mA
6.
U-LO
Minimum signal from sensor
0…10.0000/0..20.0000
7.
U-HI
Maximum signal from sensor
0…10.0000/0..20.0000
8.
P-LO
Minimum displayed value
± 999999
9.
P-HI
Maximum displayed value
± 999999
10.
FILT
Filtration level
0-99
11.
DP
Number of decimals of the result
0-3
12.
ADR
MODBUS address
RS485
0-99
13.
BAUD
MODBUS transmission speed
19200 / 38400
57600 / 115200
14.
BEP
Keys audible signal
Other
ON/OFF
15.
LED
Display brightness level
0-9
16.
FAC
Restoring factory default settings
17.
PAS
Password
X-0000 –non-active
Menu exit/abortion
Parameter confirmation/abortion
Blinking measurement value preceded by C symbol on the display means the result overflow (the
result is not contained within 6 positions of the display). In order to display older part of the
result, press .
Exceeding of measurement range (10V or 20mA) results in blinking of the displayed value

www.wobit.com.pl
Manual -MD150A –27.10.2014 –v.1.2
page 7
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.
4Configuration of measurements
4.1 Configuration of 0-10V / 0-20mA input
Depending on the output standard of the applied sensor, you should select an appropriate process
display input mode. It is achieved with 5.INPUT. For sensors with voltage output or at
measurements of signals from potentiometer sensors, set 0-10V mode. For sensors with current
output with range 0-20mA (e.g. 4-20mA) set 0-20mA mode.
4.2 Configuration of measurement units
MD150A process display enables converting the sensor signal into values in measurement units
specific for a given sensor. This allows for indication of e.g. measurement value in meter for distance
meter, inclination for inclinometer or pressure in bar for pressure sensor.
Four parameters are used for configuration of units:
6. U-LO –minimum value of signal from the sensor (0...10V or 0...20mA)
7. U-HI –maximum value of signal from the sensor (0...10V or 0...20mA)
8. P-LO –minimum measurement value displayed by the process display
9. P-HI –maximum measurement value displayed by the process display
Example 1) For draw wire sensor with 4-20mA output and range 0-10m, in order to display its result
in meters you should enter the following parameters: U-LO = 4.00 U-HI = 20.00 P-LO = 0 P-HI =
10.00 , and parameter INPUT -> 0-20mA.
Example 2) For analogue inclinometer with 2.5-5V output and range -20deg - +20deg, in order to
display the result in degrees you should enter the following parameters: U-LO = 2.50 U-HI = 5.00 P-
LO = -20.0 P-HI = 20.00 , and parameter 5.INPUT -> 0-10V

www.wobit.com.pl
Manual -MD150A –27.10.2014 –v.1.2
page 8
4.3 Number of decimals of the result/parameters
Parameter 11. DP specifies the number of decimals of the displayed value. If DP is set to 0, the
indicator displays only the total measurement part. For DP = 4 the result includes four decimal
places.
Parameter DP also influences the range of values of entered parameters. If DP = 0, then settings P1,
P2, P3-H, U-LO, H-HI, P-LO, P-HI can be changed only in total part in the range of -99999 to 999999.
If DP=4, the above parameters can be changed in range from -99.9999 to 99.9999
4.4 Filtering of measurements
Parameter 10.FILT specifies filtration level. The higher the filtration value (max. 99), the more stabile
indications, however, response to changes of the measured signal is slower. For example, for set
filtration equal to 99 and change of input signal from 0V -> 10V, the indicator reaches indicated
value 10V after 1 sec. (100Hz/99 ->”1).
5.Configuration of relay output
MD150A indicator 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
3. P3H - 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.
Fig. 2 Example of PK1 relay output activation depending on P1 and P3H setting and operatingl mode (MODE).

6.Digital input DIN1, DIN2
DIN1 input enables interception of measurements by MD150A-PC software. In order to activate the
function, you should check the option “DIN1 triggering” in the software.
Automatic data acquisition is stopped at this moment. The next measurement shall be intercepted by
software only at the moment of increasing slope at DIN1 input, i.e. change of the signal status from
0V to +5..+24V.
DIN2 input is used for “freezing” of a current measurement on the MD150A indicator display. The
last measured value is displayed (blinks) until DIN2 input reaches high status (+5...+24V).
Picture. 3 Example of DIN1 and DIN2 outputs control.
7.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.
(If the password is lost, you can find universal password in chapter 10)
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

www.wobit.com.pl
Manual -MD150A –27.10.2014 –v.1.2
page 10
8.USB and RS485 MODBUSR interface
8.1 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..
8.2 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:
Baud rate: 38400bps, Bits: 8, Stop Bits: 1, parity: none
Address Modbus: 1
Modbus address and baud rate of MD150T can be set with the following parameters:
12. ADR - velocity settings MODBUS (9600, 19200, 38400, 57600, 115200)
13. BAUD - address settings MODBUS (1…99)
8.2.1 Descriptions of MODBUS protocol
Implemented functions MODBUS
Function no (hex)
Description
1 (0x01)
Input status readout (relays)
3 (0x03)
Readout of X registers
5 (0x05)
Record of single bit
Type of variables used
Variable name
Description
Size
(Bytes)
Number of occupied registers
WORD
Complete number with a
sign
2
1
REAL
Floating point number
4
2

www.wobit.com.pl
Manual -MD150A –27.10.2014 –v.1.2
page 11
Map of MD150A register addressing
Address
Name
Type of
variable
Mode
(Modbus
function)
Description
0 (*1)
MESVAL_AIN
WORD
R (0x03)
Reading of measured voltage value 0-10V
(in mV) or current 0-20mA (w uA).
2-3 (*3-4)
MESVAL_REAL
REAL
R (0x03)
Indicator displayed measurement value
reading
4 (*5)
MAXVAL_AIN
WORD
R (0x03)
Maximum recorded value reading 0-10V (in
mV) or current 0-20mA (in uA).
6-7 (*7-8)
MESVAL_REAL
REAL
R (0x03)
Maximum recorded value reading
*for devices with address starting with 1 value(offset address +1)
R –reading register, W - record
TIP: 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
Example of MODBUS communication table
Example table of MESVAL_AIN registry reading (voltage value (in mV) / current value (uA))
Request (MODBUS MASTER -> MD150A)
Response (MD150A -> MODBUS MASTER)
Device address
0x01
Device address
0x01
Function
0x03
Function
0x03
Hi registry address
0x00
Number of Bytes
0x02
Lo registry address
0x00
Register 0x00 Hi
INT (Byte 1)
Number of Hi registries
0x00
Register 0x00 Lo
INT (Byte 0)
Number of Lo registries
0x01
CRC Hi
8 bit
CRC Hi
0x84
CRC Lo
8 bit
CRC Lo
0x0A
Example table of MESVAL_REAL registry reading (indicator displayed value)
Request (MODBUS MASTER -> MD150A)
Response (MD150A -> MODBUS MASTER)
Device address
0x01
Device address
0x01
Function
0x03
Function
0x03
Hi registry address
0x00
Number of Bytes
0x04
Lo registry address
0x02
Register 0x02 Hi
REAL (Byte 1)
Number of Hi registries
0x00
Register 0x02 Lo
REAL (Byte 0)
Number of Lo registries
0x02
Register 0x03 Hi
REAL (Byte 3)
CRC Hi
0x65
Register 0x03 Lo
REAL (Byte 2)
CRC Lo
0xCB
CRC Hi
8 bit
CRC Lo
8 bit

www.wobit.com.pl
Manual -MD150A –27.10.2014 –v.1.2
page 12
9.Technical parameters
Description
Parameter
Power supply
15 ... 36 VDC, recommended 24 VDC, min. 250mA
Sensor supply output
12 VDC, max. 200mA
Analogue input
Resolution <10000 measurement steps
(0-10V: ±1mV, 0-20mA: ±4uA)
Input resistance 30KΩ
Non-linearity error: 0,05% FSR
Temperature error: 0,03% FSR/1°C
Max. measurement frequency: 100Hz
Digital inputs DIN1, DIN2
Low status 0V (max. 2V), high status +24V (5...24V)
Relay outputs PK1, PK2
2 x 1A/125VAC, 2A/30VDC
Communication
RS485 MODBUS-RTU, default parameters 38400, 8:n:1, USB: 1.1, 2.0
Operating temperature range
0..50oC
Initial heating time
20 min.
Display
6 digits, height 13.5 mm
Housing
Height : 45
Width: 92 mm
Length : 81 mm
Weight
200g
Leak tightness degree
IP40, from panel head - IP65
Universal password
3145
FSR –full scale range