91638 Sample Specific Assessment Guide - NZQA

Level 3 Digital Technologies 91638 (3.47) Specific Assessment Guide | |
Title Demonstrate understanding of complex concepts used in the design and
construction of electronic environments Credits 4
|Teacher introduction |
Technology assessment guides have been produced to help teachers develop
their own specific assessment guides. Examples of specific assessment
guides, developed from the common assessment guide for each standard, have
been produced as part of the external assessment resources for level 3
Technology.
The specific assessment guides also show a variety of ways (ie, case study,
research, practice) to produce external assessment material. The material
in the candidate exemplars for each standard reflects the content and
context of the specific assessment guides.
Teachers can adapt a common assessment guide and / or a specific assessment
guide to suit the specific context of their course of teaching.
A model elevator is used as the context for learning in the assessment
exemplars for this standard. This does not imply that this is the only
context or method for assessing this achievement standard. The model
elevator as an example here is used to assist candidates to gain and
demonstrate an understanding of the complex hardware and software concepts
relevant to the construction of electronic environments. This understanding
could be gained and demonstrated in any appropriate context or contexts
that incorporate complex concepts appropriate to this level of electronics
and control.
The student report must demonstrate understanding of the selected concepts
and adhere to the guidelines provided in the assessment specifications. |Candidate introduction |
You will produce a report that demonstrates understanding of complex
concepts used in the design and construction of electronic environments.
You are asked to develop an understanding of some complex hardware and
software concepts and demonstrate clearly that you understand these
concepts and how they are applied in a real-world context. This will
require you to produce a report in which you can provide text and include
schematics, diagrams, photos, graphics, etc if these assist your
explanation.
One way of gaining understanding of both hardware and software concepts is
to consider their application in an actual electronic environment. The
exemplars produced from this guide take as their context (the electronic
environment) the elevator, that is, a passenger lift that allows people to
be moved between the different levels (floors) of a building. You could
base your learning around investigating how a model elevator control module
could be developed (both hardware and software), perhaps doing some
functional modelling on a simulation programme or on breadboard. In this
way, you could, if you wished to continue with the elevator context, extend
and apply your understanding to functional modelling and prototyping of the
elevator and access assessment opportunities for the complex interfacing
standard 91639 (3.48) or the complex construction standard 91640 (3.49).
However, the elevator is just one possible scenario, and you are encouraged
to consider other real-world contexts as you develop your understanding and
appreciation of the concepts that enable electronic hardware and embedded
software to be applied and to function together in electronic devices and
installations. There are many possible such contexts, for example renewable
energy (eg wind farms), environmental monitoring (eg weather stations),
medical electronics (eg CAT and MRI scanning), and communications (eg.
mobile phone technology).
Your selection of complex hardware and software concepts from the lists
above will obviously depend on the context you choose (the electronic
environment).
You may also consider adding in additional concepts not included in the
lists in EN 5 and EN 6, for example oscillator circuits, power supplies
(DC, AC, switch-mode), impedance matching, data compression, and
communication protocols (eg I2C, RS232, etc). |Preparing the report |
To develop and demonstrate your understanding of complex concepts, it is
suggested that you consider the following approach that will assist you to
gather your evidence. The report itself is a summary of the experience and
understanding you have gained during the learning phase.
1. Context selection. Select a context (an electronic environment eg a
similar application to the elevator) that is an example of an application
of electronics and control in the real world.
2. Research phase. Carry out an initial investigation into the context and
in the process learn about the way the selected environment functions and
how the hardware and software work together to enable control of the
environment. This includes monitoring and correction strategies if the
environment moves 'out of spec' or is subjected to external threats and
stresses.
3. Concept selection phase. Identify both the hardware and software
concepts that you will apply to the context. Clearly state these as general
concepts (not just what the specific software or hardware does), for
example for the model elevator one hardware concept might be the principle
behind the operation of the DC motor interface (the H-bridge, etc), which
embodies the concept of controlling current direction and power to a motor.
One software concept might be the principle of software feedback using
flags and / or interrupts for different situations that might arise during
elevator operation, eg preventing the lift door closing on someone as they
get in.
4. Evidence collection and research phase. This is the opportunity to
investigate what might happen in different situations, eg for the model
elevator, when different conditions arise. A simulation tool could be used
here, or a control circuit (including a microcontroller) built and tested
on a breadboard, or a survey of elevator function through studying actual
control systems with the cooperation of an elevator company. Notes,
diagrams, photos, etc could be collected and sorted at this stage. A
literature or web search will also assist in expanding understanding of the
selected concepts being studied.
Note: These exercises, which add to conceptual understanding, might be
carried out as part of a holistic teaching and learning programme that also
includes development of key skills, such as interfacing and construction.
5. Report writing phase. This is the time to organise all the evidence you
have collected for your understanding of the concepts you have studied.
Remember you are going to have to convince the external assessors that you
actually understand these concepts, how they work, where they are applied
in context and (for Excellence, go a lot further and discuss their
application and limitations and compare and contrast to other examples in
other contexts, for example to extend the elevator context, their
application in escalators, conveyors, and so on).
Your report must be in your own words, to the point, and be drawn from a
range of sources and your own experiences. Your report must also be
relevant to the context you have chosen. |Candidate guidance for producing the report |
This assessment guide must be read along with the achievement standard and
the assessment specifications.
The prompts provided below are guides to producing a report that
demonstrates understanding of complex concepts used in the design and
construction of electronic environments. The prompts guide candidates to
produce evidence for all grades of the standard - Achievement, Merit, and
Excellence. It is not necessary to respond to all prompts to succeed at any
level. The later prompts guide candidates to in-depth discussion.
Each report will be assessed overall as to the level of understanding the
report demonstrates of complex concepts used in the design and construction
of electronic environments.
Your report should: . describe complex software concepts e.g. describing software flags used to
show conditions within a program, such as indicating the status of a
model train on a track . describe microcontrollers and other complex hardware concepts e.g.
describing various feedback techniques in op-amp circuits . explain complex software concepts e.g. explaining how interrupts are used
to suspend usual programme flow, such as when a second model train enters
the same section of track as the first train . explain microcontrollers and other complex hardware concepts e.g.
explaining how signals can be mixed such as audio in a summing op-amp
circuit . discuss complex software concepts e.g. discussing why flags are selected
for a programme, such as when handling requests from multiple sources in
a model train system . discuss microcontrollers and other complex hardware concepts e.g.
discussing why multiple stages of amplification rather than a single
stage is more appropriate for a pressure sensor design.
The concepts that you can select for the purposes of your report must
include both hardware and software concepts.
Suggested concepts are outlined in the achievement standard under
explanatory notes 4 and 5.
Complex software concepts include a selection from: . structuring complex programs logically . analogue to digital and digital to analogue conversion . flags . counters . interrupts . bitwise logic (ie bitwise AND and OR statements) . idea of serial data transmission, baud rate using wires, Infra Red (IR),
radio . Universal Serial Bus (USB)/Ethernet/Wireless Fidelity (WiFi) interfaces.
Complex hardware concepts include microcontrollers and a selection from: . effects of component tolerance in a circuit . effects of capacitor-resistor