enraf 862 MIT User manual

Instruction manual 862 MIT Page 1
Instruction manual 862 MIT
Multi element Interface
Thermo sensor converter
August 2006
Part no.: 4416.231
Rev. 2
Enraf B.V.
P.O. Box 812
2600 AV Delft
Netherlands
Tel. : [phone]
Fax : [phone]
E-mail : [email protected]
Website : http://www.enraf.com

Page 2
Copyright 2000 - 2006 Enraf B.V. All rights reserved.
Reproduction in any form without the prior consent of Enraf B.V. is not allowed. This manual is for information
only. The contents, descriptions and specifications are subject to change without notice. Enraf B.V. accepts no
responsibility for any errors that may appear in this manual.
The warranty terms and conditions applicable in the country of purchase in respect to Enraf B.V. products are
available from your supplier. Please retain them with your proof of purchase.

Preface
Instruction manual 862 MIT Page 3
Preface
This manual is intended for technicians involved with the commissioning and service of the Enraf Series
862 Multi element Interface Thermo sensor converter, connected to Enraf series 854 level gauges,
873 SmartRadar or 877 FDI.
For mechanical and electrical installation of the 862 MIT and the 864 MTT (Multi Thermo sensor Thermometer),
refer to the installation guides of these instruments. Refer also to the list of related documents in Appendix B.
A description preceding the technical procedures gives the technical information necessary to understand its
functioning. It is recommended to read this description prior to performing any of the procedures.
Safety and prevention of damage
Refer to the safety chapter in the instruction manual and installation guide of the related instrument for the safety
aspects of the instrument and for personal safety and safety conventions.
EC declaration of conformity
This instrument is in conformity with the protection requirements of EC Council Directive 89/336/EEC.
The CE conformity marking fulfills the provisions of
EN 50081-2 Generic Emission Standard
EN 50082-2 Generic Immunity Standard
73/23EEC Low Voltage Directive
when installed, maintained and applied according to requirements as specified in this manual.
Legal aspects
The information in this manual is the copyright property of Enraf B.V., Netherlands.
Enraf B.V. disclaims any responsibility for personal injury or damage to equipment caused by:
• Deviation from any of the prescribed procedures;
• Execution of activities that are not prescribed;
• Neglect of the general safety precautions for handling tools, use of electricity and microwave radiation.
Additional information
Please do not hesitate to contact Enraf or its representative if you require additional information.

Table of contents
Page 4
Table of contents
Preface ............................................................................. 3
1 Introduction .......................................................................... 5
1.1 Productinformation .............................................................. 5
1.2 Operatingprinciple ............................................................... 5
1.3 Measuringsequence ............................................................. 5
2 Commissioning ....................................................................... 7
2.1 Checks before starting commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.2 Selecting temperature dimension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Tank and temperature probe data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.4 Additional settings for an 877 FDI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3 Operation .......................................................................... 11
3.1 Display ....................................................................... 11
3.2 Dataitemsanderrorcodes ....................................................... 11
4 Maintenanceandtroubleshooting ....................................................... 12
4.1 Temperature error codes (item EM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.2 Temperature status request (item MQ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.3 Temperature pointer (items VP and VV) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
AppendixA ASCIItable ............................................................. 14
AppendixB Relateddocuments ....................................................... 15
Index .............................................................................. 16

Introduction
Instruction manual 862 MIT Page 5
1 Introduction
1.1 Product information
The 862 MIT (Multi element Interface Thermo sensor converter) is used for interfacing an 864 Multi Thermo
sensor Thermometer (MTT). This unit is basically a solid state electronic element selector, containing all
necessary hardware for selecting and measuring an MTT with up to 16 spot temperature elements.
The 862 MIT must always be used in combination with an 854 level gauge, an 873 SmartRadar or an 877 Field
Display & Interface. These instruments must be equipped with an MPU, HPU or OPU option board to interface
the 862 MIT.
1.2 Operating principle
The 864 MTT contains of 16 spot elements (thermocouples) equally divided over the measuring range.
The lowest element acts as the cold junction and its actual temperature is accurately measured by a Pt100
(reference resistor).
The spots which are submerged in the product are used for the average product temperature calculation; the
remaining spots are used for the average gas temperature calculation.
The optional board, located in the 854 level gauge, 873 SmartRadar or 877 FDI, calculates the average product
temperature and the average gas temperature.
When the instrument is provided with a display the temperature can be displayed. Remote readout of the
measured temperature is possible via the 977 Tank Side Indicator (TSI), the 878 panel indicator (CPI) or via tank
inventory systems such as Entis Pro.
1.3 Measuring sequence
The measuring cycle of the 862 MIT takes approximately 2 minutes and 26 seconds. In that time the following
data is measured.
Cycle Measurement Cycle Measurement Cycle Measurement
1 R 5 R 23 U
ref TC0 TC0'
2 R 6 R 24 ÷ 38 U ÷ U
test TC0' TC15 TC1
3 R 7 ÷ 21 R ÷ R 39 U
Pt100 TC15 TC1 test
4 R 22 U 40 U
gnd TC0 ref
Each resistance measurement is measured with 1 mA current and without current. The measurement without
current is an offset measurement.
In measurement cycle 1 a conversion factor is determined: Hz/ohm. With this conversion factor all other
resistance measurements are calculated. This conversion factor is determined with every measurement
(2 min 26 sec). In this way an auto calibration of the 862 MIT is obtained.

Introduction
Page 6
Figure 1.1 Measuring principle
The Pt100 resistance is measured in
measuring cycle 3 and in measuring cycle 4
the resistance of the ground wire is
measured.
The resistance value from the Pt100
resistance is converted into a temperature
value via the standard table.
This temperature value is used as reference
temperature for the thermocouples.
The first time the 862 MIT is switched on
(with an MTT connected) measurement
cycles 7 ÷ 21 determines the wiring
sequence of the thermocouple wiring.
That wiring sequence is then programmed
in item MW (refer to chapter 2.3), and from
that moment on, measurement cycles 7 ÷ 21
checks if all elements are still connected in
the same order.
In measurement cycle 40 another conversion
factor is obtained (Hz/V) which is used for all
the voltage measurement values in the same
way as with the resistance measurements.

Commissioning
Instruction manual 862 MIT Page 7
2 Commissioning
For information how to program items, refer to the instruction manual of the used level gauge or to the instruction
manual of the 847 Portable Enraf Terminal.
For the connection of the 862 MIT to the instrument, refer to the installation guide of the 862 MIT and the
installation guide of the used level gauge.
The items which should be programmed / checked, as described in the next sections, must be addressed to the
instrument where the 862 MIT is connected.
2.1 Checks before starting commissioning
Warning
Do not open any of the instruments covers while power is still connected.
• Check the connections of the 864 MTT (refer to installation guide 862 MIT)
• Check the connection to the instrument (refer to installation guide 862 MIT). Check that the screen of the
cable is grounded inside the cable gland.
• Check the ground connection of the 862 MIT / 864 MTT
(refer to installation guides 862 MIT and 864 MTT)
• Read the sensitive length from the 864 MTT label (or the engraved value on the extension tube).
• Read the overall length from the 864 MTT label and verify the nozzle height with respect to the zero point
(datum plate) of the tank.
2.2 Selecting temperature dimension
When the temperature dimension has to be changed from default, all temperature data items will be presented to
the new dimension (the format remains the same).
Item Name Description
W2= Protection level 2 Enter protection level 2.
TD= Temperature dimension Selects the temperature dimension (format remains unchanged).
This item contains one character, which can be:
C : degrees Celsius
F : degrees Fahrenheit
Default set on: C (°C).
EX Exit Exit protection level

Commissioning
Page 8
Figure 2.1 MTT definitions
2.3 Tank and temperature probe data
Item Name Description
W2= Protection level 2 Enter protection level 2.
MR= Reference resistance Internal floating point format (default: +.00000000E+00 ).
The reference resistance value must be set on: +.22200000E+03.
MT= Element type Three characters (default: TPL).
The element type must be set on: ‘TPL’.
MN= Number of elements Two digits (default: 16). The number of elements must be set on: 16.
EX Exit Exit protection level.
Wait for approximately 3 minutes and then continue with the items on the next page.

Commissioning
Instruction manual 862 MIT Page 9
Item Name Description
W2= Protection level 2 Enter protection level 2.
RW MTT wiring request This is a data item which holds the detected wiring sequence from the
thermocouple wiring (blue wires). The wiring sequence must be copied
in item MW.
Item RW can only be read if item MW is set to its default value (all 0’s).
MW= MTT wiring connections Sixteen hexa-decimal characters (default: 0000000000000000).
Give the found wiring sequence from item RW into item MW.
Note 1:
When entering item MW with the Portable Enraf Terminal, the display
will be cleared after entering the 15 character. Continue with
th
entering the last character and press return. All 16 entered
characters will be repeated at the top line of the PET.
Note 2:
To disable the first spot temperature element (Pt100) from the
average product temperature calculation, set the first character of
item MW to ‘F’, and all the others as found in item RW. Only valid
from software versions: MPU B1.3, HPU B2.1 and OPU B1.1.
MK= Sensitive length MTT Format according to item LD (default: +030.0000).
Check the value for the sensitive length of the MTT on the identification
plate of the 864. Enter that value in item MK.
MO= Temperature element Format according to item LD (default: +000.0000).
offset Item MO represents the distance from tank zero to the first temperature
element (Pt100 spot). MO can be found as follows: height mounting
nozzle 864 MTT (with respect to tank zero) - overall length.
MI= Switch hysteresis Format according to item LD (default: +000.1000 m).
The distance MI is a hysteresis around the switching point of the
temperature elements.
MP= Product immersion depth Format according to item LD (default: +000.5000 m).
The distance MP specifies the minimum required liquid level above a
thermocouple before it is taken in the average product temperature
calculation.
MG= Gas immersion depth Format according to item LD (default: +000.5000 m for 854 / 873 and
+000.1000 m for 877).
The distance MG specifies the minimum required distance below a
thermocouple before it is taken in the average gas temperature
calculation.
VR= Reference voltage Internal floating point format. Must be set to: +.18500000E+04.
VT= Test voltage Internal floating point format. Must be set to: +.13567000E+04.
TU= Temperature status One character (default: ‘T’).
conversion This item is used to indicate the temperature status character incase of
a reduced or not guaranteed temperature accuracy.
EX Exit Exit protection level.

Commissioning
Page 10
2.4 Additional settings for an 877 FDI
Item Name Description
W2= Protection level 2 Enter protection level 2.
OB= Option board Three characters. This item informs the XPU what option board is
installed. That can be:
MPU - for MPU optional board
HPU - for HPU and OPU optional board
EG= Enable temperature One character; either “D” or “E”. With this item can be selected if
transmission the 877 FDI shall answer on a temperature request (C-record),
addressed to the connected level gauge.
E - transmission of temperature record is enabled
D - transmission of temperature record is disabled
TF= Temperature source One character; either “I” or “E”. This item selects if there is a
selection temperature measurement inside the indicator (Internal) or to be
fetched from the Enraf field bus (External).
I - Internal (MPU, HPU, or OPU option board installed)
E - External
EX Exit Exit protection level.

Operation
Instruction manual 862 MIT Page 11
3 Operation
3.1 Display
For operation of the display and the information on it, refer to the instruction manual of the applicable level gauge
or 877 FDI. Below, only an overview is given which display formats gives information about the 862 MIT Multi
element Interface Thermo sensor converter / 864 MTT Multi Thermo sensor Thermometer.
Display format Displayed information
AProduct level and average product temperature
CAverage gas temperature and status
DAverage product temperature and status
3.2 Data items and error codes
Below, a summary is given of the available data items and error codes. There is no operational command.
Item Description
AG Measured / Average gas temperature
AP calculated data Average product temperature
MQ Temperature status request
MU Test resistance (standard floating point format)
U0 - UF Calculated spot positions
V0 - VF Spot temperatures
VV Temperature pointer value (first set the temperature
value pointer item VP, then request for item VV)
EM Error codes Error MPU / HPU / OPU request
FM Fatal MPU errors
FH Fatal HPU / OPU errors
M0 Last fatal MPU error
H0 Last fatal HPU / OPU error

Maintenance and trouble shooting
Page 12
4 Maintenance and trouble shooting
4.1 Temperature error codes (item EM)
This item contains the most recent temperature error encountered by the MPU, HPU or OPU board.
Error codes 22xx are from the MPU board, 24xx are from the HPU board and 26xx are from the OPU board.
2x00 No error, value at initialization 2x69 CRC error )
2x50 Element connected to CN2-0 detected absent
2x51 Element connected to CN2-1 detected absent
2x52 Element connected to CN2-2 detected absent
2x53 Element connected to CN2-3 detected absent
2x54 Element connected to CN3-4 detected absent
2x55 Element connected to CN3-5 detected absent
2x56 Element connected to CN3-6 detected absent
2x57 Element connected to CN3-7 detected absent
2x58 Element connected to CN4-8 detected absent
2x59 Element connected to CN4-9 detected absent
2x60 Element connected to CN4-10 detected absent
2x61 Element connected to CN4-11 detected absent
2x62 Element connected to CN5-12 detected absent
2x63 Element connected to CN5-13 detected absent
2x64 Element connected to CN5-14 detected absent
2x65 Element connected to CN5-15 detected absent
2x67 Wrong sequence number in transmitted data;
862 MIT will be reset. )
1
2x68 Overflow bit set in transmitted data. Check thermocouple
wiring connections
) Communication error with 862 MIT; check wiring and
1
grounding between 862 MIT and connected instrument
) Check on too high leak current
2
*) Refer to section 1.3 Measuring sequence
1
2x72 Item RW determined, but not copied into MW
2x73 Syntax error in item MW (compare MW with RW)
2x74 Unable to detect wiring sequence. One or more elements
were detected absent
2x75 General MIT error (R_ref and / or R_gnd failed) *)
2x76 U_ TC0 and / or U_ TC0' failed *)
2x78 Item MR not set to any value
2x79 Calibration fail; items VR and / or VT not (correct) set
2x80 Ratio R_test / R_ref invalid (should be 0.75) *)
2x81 Ratio U_test / U_ref invalid *)
2x82 R_ TC0 >100 ohm (thermocouple 0 open loop) *)
2x83 330 ohm > R_ TC0' > 430 ohm. Check if CN1-19 is
unconnected and if item MR has the correct value )
2
2x86 Leak current too large. Check with item VV10,00. This
should be lower than 250 nA. Check grounding of all
cabling to 862 MIT and level gauge.
2x87 R_ TCi error. Thermo elements possibly not connected in
the right order. *)
2x88 On resistance of one of the FETs is too high. Check if
item MR has the correct value
2x89 Measured thermo voltage of an element is too high
2x90 Floating point calculation failure (on processor board)
2x92 No communication with MIT during last 10 seconds.
Check cabling between 862 MIT and connected
instrument.
If one element is detected absent it could very well mean that the thermocouple wiring to the 862 MIT is not
correct connected or the FET switch in the 862 MIT is not correct working.
4.2 Temperature status request (item MQ)
Four bytes status information (B0 B1 B2 B3) with the following meaning:
Status byte 0:
Contains the characters ‘0’ ÷ ‘F’, indicating the highest immersed spot element of the MTT. At start up: ’I‘.
Status byte 1: Status byte 2:
bit 0 : General temperature fail bit 0 : Last valid level used
1 : Fail in average product temperature 1 : Manual level used
2 : Fail in average gas temperature 2 : Level time out
3 : Level exceeds lowest spot element 3 : Device not calibrated
4 : Level exceeds highest spot element 4 : Exceeding differential temp. range
5 : Spot element fail (one or more spots defect) 5 : Out of specified temperature range
6 : 1 6 : 1
7 : 0 7 : 0
Status byte 3: For decoding of the status bytes, refer to the
bit 0 : No previous store command ASCII table in appendix A.
1÷5 : 0
6 : 1
7 : 0

Maintenance and trouble shooting
Instruction manual 862 MIT Page 13
4.3 Temperature pointer (items VP and VV)
With the temperature value pointer item VP several important calculation results can be selected which then can
be requested by the temperature pointer value item VV.
First load the pointer (item VP) with 2 digits (v, w), a separator which can be a ‘ .’ (point) or a ‘ ,’ (comma), and
another 2 digits (x, y) according to the table below.
v w .x y Selected value Dimension
0 0 .0 1 - 1 5 U - U µV
0 1 .0 0 - 0 1 U - U
TC1 TC15
TC0 TC0'
µV
1 0 .00 Sigma leak current µA
1 0 .01 U / U
1 0 .02 Element being measured
1 0 .07 f
1 0 .08 f
ref test
R_ref
R_ref-offset
Hz
Hz
2 0 .0 1 - 1 5 R - R Ω
2 1 .0 1 - 1 5 R - R
2 2 .0 0 - 0 3 R , R , R , R
on1 on15
TC1 TC15
TC0 TC0' gnd Pt100
Ω
Ω
3 0 .0 0 - 1 5 Element temperature in 8 digits depending on item TD
Next, the item VV holds the value of the selected quantity in floating point format.
Item Name Description
VP= Temperature value pointer Temperature value pointer; format: 2 digits, separator, 2 digits
(refer to table above).
Example: VP=22.03: value pointer loaded to request the Pt100 element
resistance
VV Temperature pointer value Temperature pointer value; standard floating point format.
This item hold the value requested by item VP (refer to table above).
Example: the requested Pt100 element resistance.

Appendix
Page 14
Appendix A ASCII table

Appendix
Instruction manual 862 MIT Page 15
Appendix B Related documents
Installation guide 862 MIT MIR
Installation guide 863 MTT Multi Thermo sensor Thermometer
Installation guide 854 Advanced Technology Gauge
Instruction manual series 854 ATG level gauge
Installation guide 854 XTG Servo gauge
Instruction manual series 854 XTG level gauge
Installation guide 873 SmartRadar Control Unit & Antenna Unit
Instruction manual 873 SmartRadar
Installation guide 877 FDI Field Display & Interface
Instruction manual 877 FDI Field Display & Interface
Item documentation for Enraf series 854 level gauges, 873 SmartRadar, 877 FDI

Index
Page 16
Index
862MIT ................................ 5
864MTT ................................ 5
Average gas temperature . . . . . . . . . . . . . . . . 5, 11
Average product temperature . . . . . . . . . . . . . 5, 11
CE..................................... 3
Displayformat .......................... 11
Electrical installation . . . . . . . . . . . . . . . . . . . . . 3, 7
Elementtype............................. 8
Enable temperature transmission . . . . . . . . . . . . 10
Error MPU / HPU / OPU request . . . . . . . . . . . . 11
Fatal HPU / OPU errors . . . . . . . . . . . . . . . . . . . 11
FatalMPUerrors ........................ 11
Gas immersion depth . . . . . . . . . . . . . . . . . . . . . . 9
Installation Sensitive length MTT . . . . . . . . . . . . . . . . . . . . . . 9
electrical ............................. 3
mechanical ........................... 3
Items Temperature
AG ................................. 11
AP ................................. 11
EG ................................. 10
EM .............................. 11,12
FH ................................. 11
FM ................................. 11
H0 ................................. 11
M0 ................................. 11
MG.................................. 9
MI .................................. 9
MK .................................. 9
MN.................................. 8
MO.................................. 9
MP .................................. 9
MQ.............................. 11,12
MR.................................. 8
MT .................................. 8
MU................................. 11
MW ............................... 6,9
OB ................................. 10
RW ................................. 9
TD .................................. 7
TF ................................. 10
TU .................................. 9
U0-UF ............................. 11
V0-VF ............................. 11
VP .............................. 11,13
VR .................................. 9
VT .................................. 9
VV .............................. 11,13
Last fatal HPU / OPU error . . . . . . . . . . . . . . . . . 11
Last fatal MPU error . . . . . . . . . . . . . . . . . . . . . . 11
MTT wiring connections . . . . . . . . . . . . . . . . . . . . 9
MTT wiring request . . . . . . . . . . . . . . . . . . . . . . . . 9
Number of elements . . . . . . . . . . . . . . . . . . . . . . . 8
Option board . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
HPU................................. 5
MPU ................................ 5
OPU................................. 5
Product immersion depth . . . . . . . . . . . . . . . . . . . 9
Reference resistor . . . . . . . . . . . . . . . . . . . . . . 5, 8
Reference voltage . . . . . . . . . . . . . . . . . . . . . . . . 9
Safety .................................. 3
Spot elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Switch hysteresis . . . . . . . . . . . . . . . . . . . . . . . . . 9
dimension ............................ 7
element offset . . . . . . . . . . . . . . . . . . . . . . . . . 9
pointer value . . . . . . . . . . . . . . . . . . . . . . . . . 13
source selection . . . . . . . . . . . . . . . . . . . . . . 10
status conversion . . . . . . . . . . . . . . . . . . . . . . 9
status request . . . . . . . . . . . . . . . . . . . . . 11, 12
value pointer . . . . . . . . . . . . . . . . . . . . . . . . . 13
Test resistance . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Test voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Thermocouples . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Warranty................................ 2