Technical Documentation
1
MI450 Programmable transducers for RTD sensors
Measuring transducers MI4x0 series
Programmable transducers for RTD sensors
MI450
o Measuring of resistance of RTD sensors (Pt100, Pt1000, Ni100,
Cu10, ...)
o Accuracy class up to: 0.5
o Programmable input and output
o Serial communication RS232 or RS485, MODBUS protocol
o Universal AC/DC or AC Auxiliary power supply
感算商城
Technical Documentation
2
MI450 Programmable transducers for RTD sensors
PROPERTIES
o Measuring of resistance of RTD sensors (Pt100, Pt1000,
Ni100, Cu10*, ...)
o Accuracy class: 0.5 (Cu10 - Accuracy class: 1*)
o Programmable input and output
o Serial communication RS232 or RS485, MODBUS
protocol
o Universal AC/DC or AC Auxiliary power supply
o (very high speed data rate: up to 115,200 bit/s,
MODBUS protocol)
o Low power consumption
o Housing for DIN rail mounting
o Correspond to EN 60770-1: 1999
*See chapter Technical data - Accuracy.
APPLICATION
Measuring transducer MI450 is designed for use in industrial
process for conversion of nonlinear resistance sensors (RTD –
sensors) in to appropriate DC current or DC voltage signal. The
analogue output signal is proportional to the measured value
and it is appropriate for regulation of analogue and digital
devices with reasonable dependence on environmental
conditions, where they are planned to be used.
LAYOUT AND MODE OF OPERATION
Resistance on the input terminals can be measured with three
methods, two, three or four wire connection. In all cases U-I
method is used for measuring. Enforced current causes a
voltage drop (A - Picture 2) on measured RTD sensor which is
supplied to the programmable amplifier B. After A/D conversion
the signal is computed in microprocessor C. The measured value
determined by the microprocessor is assigned to the
programmable analogue output E. Communication D enables
programming of the measuring transducer and monitoring of
the measuring resistance on the input terminal.
Communication, analogue output and auxiliary power supply
are electrically insulated from other system by means of
separation transformer.
Picture 1: Block diagram
PROGRAMMING
Input and output values are programmed
1)
with MiQen setting
software via RS232 or RS485 communication. Before setting the
transducer, output value must be selected by the jumpers on
the output module
2)
. It is possible to choose between three
ranges 0…±10 V, 0…±5 mA and 0…±20 mA. Within this three
ranges it is possible to set any linear or bent (with maximum 5
break points) output characteristic.
1)
– Programming is not possible in versions without communication
2)
– Qualified person only
VERSIONS
The following transducer versions are available as programmable via communication or to be specified at the placing order:
Input
Type of
RTD
Measuring
voltage
Output Supply
Communication
Bent characteristic of
analogue output
-200° to 850°C
for Pt...,
-60° to 250°C
for Ni...,
20Ω to 10kΩ
for polinom
3)
,
-50° to 250°C
for Cu...
Pt100
Pt1000
Ni100
Cu10*
< 2.2 V
1 mA
5mA
10 mA
20 mA
4...20 mA
1 V
10 V
other on request
Universal or
RS232 or RS485
Programmable via
communication or to
be specified at the
placing order
AC:
57 V
100 V
230 V
400 V
500 V
Table 1: Versions of MI450
3)
– With program package MiQen it is possible to set 6
th
grade polynomial function
*Cu10: Accuracy class 1; see chapter Technical data.
Transducers are mounted on standard rail 35 x 15 mm (according to DIN EN 50022)
感算商城
Technical Documentation
MI450 Programmable transducers for RTD sensors
3
TECHNICAL DATA
GENERAL:
• Measured quantity: temperature from RTD sensor
• Measured principle: microprocessor sampling
INPUT:
• Measuring method: two wire connection
three wire connection
four wire connection
• Input range with programmable ratings:
RTD sensors limit values: Measuring voltage:
20 Ω to 10 kΩ < 2.2 V
• Minimum temperature range
4)
: 100° K
• Minimum differential resistance
5)
: 40 Ω (100Ω -> 140Ω)
• Lead resistance: < 10 Ω per lead
• Consumption: < 0.5 VA
4)
– Cu10: 80° K
5)
– Cu10: 3 Ω (10Ω -> 13Ω)
ANALOGUE OUTPUT:
Programmable DC current output:
• Output I
OutN
(output range end value):
• Output range values
6)
: 0…±1 mA to 0…±5 mA or,
0...±5 mA to 0...±20 mA
• Burden voltage: 15 V
• External resistance: RBmax.[kΩ]=
[mA]I
V 15
OutN
6)
- Depends of set jumpers on output module
Programmable DC voltage output:
• Output U
OutN
(output range end value):
• Output range values 0…±1 V to 0…±10 V
• Burden current: 20 mA
• External resistance: R
Bmin
.[kΩ]=
mA
20
[V]UOutN
General:
• Response time: programmable from 0.5 s to 60 s
• Residual ripple: < 1 % p.p.
• Maximum output value: limited at 125 %
Picture 2: Output transfer characteristic
N – Number of sliding windows
t – Sampling time
The output may be either short or open-circuited and it is
electrically insulated from all other circuits (floating).
All the output range end values can be reduced subsequently
using the programming software, but a supplementary error
results.
ACCURACY:
• Reference value: Input range end value
• Accuracy class:
Analogue output
7),8)
: Temperature 0.5 c
Communication
8)
: Temperature 0.5
7)
– To calculate intrinsic error, see chapter intrinsic-error (for analogue
outputs) on this page.
8)
– Cu10: Accuracy class 1, due to low resistance range (10Ω -> 13Ω).
Reference conditions:
Ambient temperature: 15…30 °C
Input: 0...100 % R
N
Intrinsic-error (for analogue outputs):
For intrinsic-error for analogue outputs with bent or linear-zoom
characteristic multiply accuracy class with correction factor (c).
Correction factor c (the highest value applies):
Linear characteristic
e
e
x
x
y
y
c
0
0
1
1
−
−
= or 1=c
Bent characteristic
bb
x
x
x
≤≤− 1
b - number of break points (1 to 5)
Picture 3: Examples of settings with linear and bent
characteristic
POWER SUPPLY:
Auxiliary AC/DC voltage (universal):
• Rated voltage (Ur): 24…300 V DC
40…276 V AC
• Frequency range: 40…70 Hz
• Power consumption: < 3 VA
Auxiliary AC voltage:
Rated voltage (Ur) Rated operating range
57.74 V
100 V
230 V
400 V
9)
500 V
9)
80…120 % Ur
9)
– to 300 V installation category III, from 300 to 500 V installation
category II – see chapter Regulations.
Table 3: Rated AC voltage for Auxiliary power supply
• Frequency range: 45…65 Hz
• Power consumption: < 3 VA
感算商城
