17
TAB_XY_VALUE5
= 0,8; 300
TAB_XY_VALUE6
= 1,6; 400
TAB_XY_VALUE7
= 3,2; 500
TAB_XY_VALUE8
= 6,4; 600
TAB_XY_VALUE9
= 12,8; 700
TAB_XY_VALUE10
= 25,6; 800
(Output will readout 325% with 1,0% potentiometer value)
2.6.13 Measurement of TC (with Custom Polynomial Linearisation) on sensor 1
PRIMARY_VALUE_UNIT
= K, °C, °F or °R
LIN_TYPE
= Custom defined TC
LIN_TYPE_2
= N/A (ignored in setup check)
SENSOR_MEAS_TYPE
= PV = SV_1, SV_2 not available
SENSOR_CONNECTION
= N/A (ignored in setup check)
SENSOR_CONNECTION_2 = N/A (ignored in setup check)
RJ_TYPE
= No Reference Junction, Internal, External (constant value) or
Sensor 2-wire or Sensor 3-wire
Connections:
Now enter the Custom TC parameters in PR_CUST_LIN Block (PA Slot 4). See 2.9.4 Custom Pol-
ynomial Linearisation, Parameter List for further details.
Remember to enter values for the RJ polynomial if RJ_TYPE is any value other than “No refer-
ence Junction”.
Example:
The parameters and coefficients for converting a special TC to a linear temperature signal.
CUSTOM_TC_NAME
= Custom TC Example
CUSTOM_TC_POLY_COUNT
= 5
CUSTOM_TC_MIN_IN
= -6500.0
CUSTOM_TC_MIN_OUT
= -100.0
CUSTOM_TC_MAX_OUT
= 1200.0
A TC input of 5000 µV and an RJ temperature of 25ºC will make POLY_3 the active and the out-
put will be:
U
RJ
= -3.94 * 10
-1
+ 3.94 * 10
1
* 25 + 2.65 * 10
-2
* 25
2
- 1.11 * 10
-4
* 25
3
= 1000 µV
This voltage is to be added to the TC voltage (5000 + 1000), and the resulting temperature will be:
4.18 + 2.26 * 10
-2
* 6000 + 1.41 * 10
-7
* 6000
2
+ 1.50 * 10
-11
* 6000
3
- 1.35 * 10
-15
* 6000
4
=
146.3 °C
See 2.9.3 Custom polynomial linearisation, Description for formula and further details.
CUSTOM_TC_POLY_X
max. input
limit in μV
for POLY_X
4th degree
coefficient
for POLY_X
3th degree
coefficient
for POLY_X
2th degree
coefficient
for POLY_X
1st degree
coefficient
for POLY_X
0 degree
coefficient
for POLY_X
CUSTOM_TC_POLY_1
-3200.0
-3.84E-13
-5.65E-9
-3.36E-5
-6.10E-2
-8.44E1
CUSTOM_TC_POLY_2
3500.0
-8.13E-15
7.29E-11
-4.18E-7
2.53E-2
-1.08E-2
CUSTOM_TC_POLY_3
10000.0
-1.35E-15
1.50E-11
1.41E-7
2.26E-2
4.18
CUSTOM_TC_POLY_4
30000.0
3.49E-18
2.19E-12
-1.53E-7
2.68E-2
-9.26
CUSTOM_TC_POLY_5
70000.0
6.27E-17
-8.76E-12
5.34E-7
8.69E-3
1.65E2
3th degree
coefficient
2th degree
coefficient
1st degree
coefficient
0 degree
coefficient
CUSTOM_TC_RJ_POLY
-1.11E-4
2.65E-2
3.94E1
3.94E-1
