AS064-ILST-NDHHDD Version 2 -- NTC DAS Hub Hardware Design Document - Signed

7/26/2019 AS064-ILST-NDHHDD Version 2 -- NTC DAS Hub Hardware Design Document - Signed

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Memorandum ASAQ2013-017


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Summary

This document contains the Hardware Design Documentation (HDD) of the NTC Acquisition

Unit This HDD contains design information about all hardware specially designed for this

device.

OPERATING AND SAFETY SYMBOLS

Symbols used on the Instrument and in the manual

Instruction manual symbol affixed to product. Warns and cautions the

user to refer to respective manual procedures to avoid personal injury

or possible damage to the instrument.

Affixed to the instrument which contains static sensitive devices. Use

anti-static handling procedures to prevent electrostatic

discharge damage to components.

IMPORTANT: Calls attention to a procedure, practice or condition that requires special attention by

the user.

CAUTION: Calls attention to a procedure, practice or condition that could possibly cause

damage to the instrument.

WARNING: Calls attention to a procedure, practice or condition that could possibly cause bodily

injury or death.

IMPORTANT:

The information contained in this document is subject to change without notice

!


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Contents

1 Introduction 5

1.1 Product identification 5

1.2 Purpose of the product 5

2 Maintenance NTC controller board 6

2.1 WARNING: 6

2.2 General 6

2.2.1

Declaration of Conformity NTC Hub and Ethernet controller 7

3 Overall hardware design 8

3.1 Ethernet controller board. 8

3.2 NTC acquisition unit. 8

3.3 Description 9

3.4 Control and Measurement mechanism 9

3.4.1 Schematic diagram 11

3.4.2 Construction 11

3.4.3

Specification 12

3.4.4 Schematic diagram 12

3.4.5 Construction 12

3.4.6 Cabling 13

3.4.7 Component list 13

3.4.8 Thermal design 13

(15 pages in total)


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1 Introduction

This document contains the Hardware Design Documentation (HDD) of the ILST NTC

Acquisition Unit. This HDD contains design information about all hardware specially designed

for this device. For information concerning standard parts used in this project, see supplier

delivered documentation.

1.1 Product identification

System number : AS064

System name : ILST DAS-bus upgrade to Ethernet

1.2 Purpose of the product

The ILST NTC acquisition unit can be used to measure the average wind speed.

A single NTC unit can maximally acquire data from 48 NTCs.


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2 Maintenance NTC controller board

2.1 WARNING:

The NTC Hub contains an embedded computer and a power supply, which are procured from a

general supplier. For safety reasons it is important that the user is aware of the safety related

information of the supplier documentation. In this document only safety related information and

maintenance instructions concerning the NLR developed products are given.

IMPORTANT:

For maintenance instructions of apparatus of other suppliers, please refer to the relevant supplier

documentation.

2.2 General

CAUTION:

CONTROL OF ELECTRO STATIC DISCHARGE (ESD)

Static-safe handling and servicing of electronic components and assemblies

is strongly recommended

All solid-state devices can be damaged by static electricity

Basic static damage preventive methods are:

1. Wear a wrist-strap. Remember to put it on and connect to ground before beginning work.

2. Work only on a grounded conductive surface or mat. DO NOT insulate work from the

conductive surface with bubble wrap, clear plastics, paper, or white or pink foam.

3. Keep all plain plastics and non-conductors out of your static-free area.

4. DO NOT allow ungrounded personnel to touch static devices or printed circuit boards.

5. Treat all components as if they are static-sensitive.

6. Transport all static-sensitive components and printed circuit boards in static shielded bags or

black conductive boxes.

7. Use only soldering irons that have grounded tips and zero-crossing heat controls to eliminate

EMI.

8. DO NOT use ohmmeters that have more than 25 Volts on their test leads. Always touch

ground first before probing the device.

9. Turn off power before removing the printed circuit board from the instrument. Be sure all test

equipment is grounded.

10.Use a conductive de-soldering device.

THE ULTIMATE RELIABILITY OF THE SYSTEM DEPENDS

ON HOW WELL THE BASIC RULES ARE FOLLOWED WHILE HANDLING AND SERVICING!!

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2.2.1 Declaration of Conformity NTC Hub and Ethernet controller

Nationaal Lucht- en Ruimtevaartlaboratorium

National Aerospace Laboratory NLR

ManufacturersDeclaration of Conformity

PRODUCT IDENTIFICATION:Product : ILST DAS-bus upgrade to Ethernet.

Model: DAS-bus to Ethernet converter, Part Number NLR-AS064

Ethernet controller, Part Number NLR-AS064

Units concerned: Refer to TCF, Memorandum ASAQ-2013-xxx

MEANS OF CONFORMITY:

EMC Directive89/336/EEG, 92/31/EEG, 93/68/EEG:Power supplies: Immunity standards: EN61000-6-2

Emission standards: EN61000-6-4

Low Voltage Directive 73/23/EEG and 93/68/EEG:

General Standard: EN61010-1/A2, Safety requirements for electrical equipment for measurement,

control and laboratory use.Power supplies: EN60950, Safety of IT equipment.

Technical construction File:TCF prepared: G. Camphorst

TCF number: Memorandum ASAQ-2013-xxx

MANUFACTURER: National Aerospace Laboratory NLRP.O Box 90502

1006 BM Amsterdam

The Netherlands

Tel: +31 (0)20 511 3113

Fax: +31 (0)20 511 3210

We declare, under our sole responsibility, that the product described conforms with the requirements of

the EU- Directives; Low Voltage Directive 73/23/EEG and 93/68/EEG

EMC Directive 89/336/EEG, 92/31/EEG, 93/68/EEG

Date of issue: xx-11-2013

Division: Aerospace SystemsDepartment: ASAQ

Location: Marknesse

Name: T ter Meer

Title of signatory: Project Manager ILST DAS-bus upgradeSignature:

NOTE:

Signed copy available


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3 Overall hardware design

The DAS-bus upgrade project as described in this document consists of the following activities:

Production of one Ethernet controller board.

Production of one NTC Acquisition Unit.

This document described the design of the Ethernet controller board and the NTC Hub.

This document also provides the complete production files for both the board and the NTC

Hub. The firmware for these devices is described in memorandum ASAQ-2013-XXX

3.1 Ethernet controller board.The Ethernet controller board is designed as a multifunctional digital interface, and is provided

with an Ethernet 100Mbps link which will be connected to the data acquisition host system and

is software configurable. The controller board is provided with an embedded Toradex Colibri

SODIMM computer with Ethernet connection. The same board is also used in the Cu MkIII for

digital board replacement, and is applied in the DAS Hub for the Ethernet connection.

For an more detailed description of the Ethernet Controller board as applied in the NTC Hub,

NLR -Memorandum ASAQ-2013-015:ILST DAS-bus upgrade to Ethernet: DAS

Hub .

3.2 NTC acquisition unit.

The hardware to control the NTC device is based on the non-CU device (DAS-Hub)

hardware.. To make the unit capable to control the NTC units the following

modification will be performed to the non-CU hardware.

The major differences between the NTC Acquisition unit and the Das-Hub are:

Strobes: only 1 strobe will be applied instead of 8.

BCD/BIN: only the BCD bus will be available.

The BCD/ BIN switch will be removed from the front panel, the BCD/BINcontrol will be fixed set to BCD.

1 2-wire step connector, Souriau 10-pol female will be added to the front panel


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3.3 Description

The NTC Acquisition unit is designed to measure the average wind speed.

One NTC unit can maximally acquire data from 48 NTC's. The measurement principle

is the following:

The unit measures the power required to keep an NTC at a certain temperature.

This power is a measure for the cooling of the NTC by the air flowing

over/around the NTC.

The cooling is proportional with the (average) speed of the airflow, and thedifference between the temperature of the air and the temperature of the NTC.

The effects of the temperature of the air is compensated for by performing a 2-

nd measurement at a different NTC temperature.

The set of two power measurements per NTC is presented as the measurement result.

This result is fed through a calibration to produce an airspeed value.

3.4 Control and Measurement mechanism

The NTC unit has two I/O channels:

1. A BCD DAS bus interface. The DAS bus interface can only be used to read a

measurement value from the NTC unit. The NTC unit does have some traces of

status word hardware; This hardware generates a status word that gives

information w.r.t. the local/remote setting of the NTC unit, and the

integration/averaging time selected (using the front-panel only..). The

integration time is most interesting, because it also indicates how long a

conversion with the NTC unit will take. Unfortunately, there is no way to read

the status word from the device.

2. A 2-wire scanner interface. The 2-wire scanner interface can be used for two

things:

o to determine if the currently selected NTC is the 'number zero'. If that is

so then the 'home' signal of the scanner interface is active.

o The scanner interface can be used to 'step' through the NTC channels.

Note that the 'scanner' part of the NTC unit is not a 'real scanner' in the sense of a

mechanical stepper: The 'scanning' element in the NTC unit is a TTL counter. For this


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description, the NTC unit will however be described in 'scanner' terms, because that is

how its functionality shows up externally.

The NTC unit has a fixed 'cycle' for performing measurements. This cycle corresponds

with 97 'scanner steps'. The reference point of the operation is the 'home' position of the

scanner. This is also the 'position' of the scanner when it is not being used to perform a

measurement.

The measurement cycle starts when the first step pulse is issued. The NTC's unit's

response to this pulse is the following:

It makes the NTC 1 the currently 'active' channel. That means that the data that

is read from the BCD DAS bus is the measurement value of NTC number 1(subject to the remarks as described below..)

It starts heating all NTC's to the 'low' NTC temperature. There is a fixed 'settling'

time for this temperature transient.

When the (temperature) the settling time is expired, a measurement is

(automatically) started. This measurement means that the pulses from the

voltage-controlled-oscillators (VCO) of all 48 NTC's are counted in 48 counter

registers. The measurement time is called the integration time. This integration

time can (only..) be adjusted by means of the local (front) control panel of the

NTC unit. The integration time can be set to either 5, 10, 20 or 50 seconds.

During the temperature settling time and the measurement time, the bit 18 of the BCD

data that can be read from the NTC unit is '1'; meaning that a measurement value of >

20000 will be read from the device. Once the measurement is finished, the bit 18 of the

data is 'cleared', and the real measured number of VCO pulses counted in the register of

NTC 1 can be read from the NTC unit by means of the DAS bus.

Once the measurement for the low temperature is done, the measurement results of all

47 other NTCs can also be read from the NTC unit, by pulsing the scanner control

wires. Each pulse on the scanner control wires selects the next NTC count register,which can subsequently be read using the DAS bus.

When reading the data from NTC 48 is finished, a next scanner pulse will initiate a

sequence of events that is very similar to the one caused by pulsing from the home

position to position '1':

The selected NTC 'channel' is again set at NTC 1.

The NTC's are heated to the 'high' temperature. A (different) temperature settling

time is taken into account so that the NTC's can stabilize at the new (high)

temperature.


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After the temperature settling time, the counter registers are reset, and the

number of pulses from the VCO's is measured for the integration time.

When that is done, the bit 18 of the data read from the NTC unit is cleared, and

it is again possible to read the number of pulses counted for NTC 1 by means of

the DAS bus.

As for the high temperature, here too the scanner control wires can be used to select

next NTC registers. This allows for all NTC 'high' temperature count values to be read.

After 47 more scan pulses, the NTC unit should be -once more- in the 'home' position.

A next measurement could be started by giving a scan pulse on the scanner interface.

As can be read from the previous description, the NTC unit is a bit of a 'one-trick-dog'.

It can measure up to 48 NTC channels, but the way it does that is quite fixed in the

hardware of the device. Also, the NTC unit is a quite 'slow' device: the temperature

settling times are in between 5 seconds and 25 seconds, the integration time is between

2 x 5 seconds and 2 x 50 seconds. The effective measurement time of this device is

roughly a few measurement per minute.

3.4.1 Schematic diagramThe schematic diagrams of the Ethernet controller board are available in:

NLR -Memorandum ASAQ-2013-015: Detailed Design Document of the DAS Hub

3.4.2 Construction

The Ethernet controller is constructed as an 8-layer Euro card of 100 x 160 mm. The board is

equipped with a 64 or 96 pol DIN connector and a RJ45 connector at the top. Components are

mounted on both sides using SMT techniques. The Colibri module is mounted horizontal like a

piggyback. The maximum component space at the bottom of the board is limited to 6mm. The

maximum component space at the top is limited to 16 mm. For the lay-out of the board see

drawing see also NLR -Memorandum ASAQ-2013-015: Detailed Design Document of

the DAS Hub.


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connector used. The position of this switch will be used by the firmware to check if the correct

nonCU type is set by the Host.

3.4.3 Specification

Dimensions of unit: 263 x 482,2 x 43.6 mm (LxBxH)

Number of channels: 8

Type of DAS-bus: BCD.

Power: 250V/50Hz ,Power consumption: 9 Watt maximal

Temperature: 15oC to 25

oC

Humidity: 20% up to 80%, non condensing.

Cleanliness: at least visible clean.

3.4.4 Schematic diagram

The schematic AS016-C-200 represents the wiring between the Ethernet controller board and

the power supply, switches and connectors. For the schematics of the Ethernet controller board,

see NLR -Memorandum ASAQ-2013-015: Detailed Design Document of the DAS Hub.

3.4.5 Construction

As housing for the converter module, a standard aluminium housing as shown in figure 5.1 will

be used. This housing is provided with extruded sleeves to mount the Ethernet controller

Eurocard board and Bezels on both sides. One side is provided with a mains / filter / switch

entree, the other side contains one DAS-bus connector, one strobe connector, and one Souriau

connector.. The filter / switch also contain the main fuse. For the actual lay-out of the drawing

converter box see AS016-C-400.

Take care, first to remove the power connection before openings of this box !

Figure 5.1 Converter box housing

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3.4.6 Cabling

The converter box will be wired internally conform the schematic diagram AS016-C-200. For

the external cabling the existing DAS-bus cabling, strobe cabling and mains supply cabling can

be reused.

3.4.7 Component list

Component list xxx

Item Description Partnumber / Farnell Manufacturer1HE 19 housing series 180 32180011 / 1171722 BIM / Farnell

A1 Ethernet controller board NLR

UN1 Power supply 240V/50Hz 5V/3A TML15105C/1242584 Traco / Farnell

PR1 Sub-D 37 Pol Female chassis

PR2 5-Pol DIN connector female chassis Farnell 181-4800 Lumberg

PR3 10 Pole Souriau 851 connector 851-00- Souriau

PR5 Ethernet RJ45 dual connector 09452451102/1170278 Harting/Farnell

PR4 BNC connector isolated 13-28 / 1169702 Multicomp/Farnell

PR100 Mains Filter/switch/ fuse 240V / 2A RIQ-0242-H2/1101086 Roxburgh/Farnell

SK1,2 Miniature toggle switch 1pol SP 7101SYZBE/957-4824 C&K

LE1-3 Panel LED 12V Green 19031251 / 1105216 CML / Farnell

3.4.8 Thermal design

The Converter box is a completely closed steel/aluminium box and not provided with forced

cooling provisions, however the bottom and top plates are provided with ventilation grooves.

The expected internal heat generation of the power supply and Ethernet converter box ismaximal 5 Watt and typical 1 Watt. This Heat is hand over to the air inside the box and finally

transferred to the walls of the box. The expected temperature rise inside the box shall be

minimal


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Documents

AS064-ILST-NDHHDD Version 2 -- NTC DAS Hub Hardware Design Document - Signed