P10503 Preliminary Test Plan Document
Top Customer Needs: Ensure Safety, Functional Subsystems, Carriage Velocity Control, Ease Of Use,
Hardware Specifications
I)
Ensure Safety, Carriage Velocity Control
a. Determine safe high voltages
b. Determine velocity of carriage and lifting systems to avoid damage to operator or
product
II) Functional Subsystems, Hardware Specifications
a. Determine nominal values
b. Determine if ‘expose in dark’ concept chosen adequately fits project needs in terms of
stray light, allowed wavelengths
III) Ease Of Use
a. Ensure that operator can easily use user interface with minimal to no documentation
although documentation will be provided
Test Plans to meet above Needs:
I)
Perform Experiment (generally for testing mechanical parts/wiring)
Sample of an experiment:
EXPERIMENT PERFORMED BY: Jeff Robble
PROBLEM: After DAQ hook-up, both paper feed and transfer drum would activate
simulataneously. Reason why is what needs to be found out by this
experiment.
HYPOTESIS: Possibly some wires were crossed or both paper feed/transfer drum
hooked up to same relay.
OBSERVATIONS:
NI DAQ 6602
PFI36 / CTR0 out (pin 5) - paper feed control
PFI32 / CTR1 out (pin 9) - transfer drum control
When both controls hooked from DAQ to respective relays the following
behaviors are observed:
1. Generating continuous pulses
[EXPECTED]
2. Generating continuous pulses
[EXPECTED]
3. Generating N pulses on PFI36
[NOT EXPECTED]
4. Generating N pulses on PFI32
[NOT EXPECTED]
on PFI36 activates paper feed only.
on PFI32 activates transfer drum only.
activates both paper feed and transfer drum.
activates both paper feed and transfer drum.
When the transfer drum control is disconnected the following behaviors are
observed:
1. Generating
[EXPECTED]
2. Generating
3. Generating
4. Generating
continuous pulses on PFI36 activates paper feed only.
continuous pulses on PFI32 does nothing. [EXPECTED]
N pulses on PFI36 activates paper feed only. [EXPECTED]
N pulses on PFI32 activates paper feed only. [NOT EXPECTED]
When the paper feed control is disconnected the following behaviors are
observed:
1. Generating
2. Generating
[EXPECTED]
3. Generating
4. Generating
EXPLANATION:
continuous pulses on PFI36 does nothing. [EXPECTED]
continuous pulses on PFI32 activates transfer drum only.
N pulses on PFI36 activates transfer drum only. [NOT EXPECTED]
N pulses on PFI32 activates transfer drum only. [EXPECTED]
Page 3-25 of the NI DAQ 6602 Manual shows a table of counter pairs:
CTR0
CTR2
CTR4
CTR6
<->
<->
<->
<->
CTR1
CTR3
CTR5
CTR7
"This pairing allows some counter signals to connect to signals on the other
counter."
The NI website
(http://digital.ni.com/public.nsf/allkb/485201B647950BF886257537006CEB89#case
3) explains:
"Generating a finite pulse train and another counter task on the same device
in LabVIEW with NI-DAQmx. For any device which uses the STCII chip
(CompactDAQ, E and M Series) a finite pulse train generation reserves both
counters.
When performing a finite pulse train generation, one counter generates the
pulse train, and the other counter generates a pulse that acts as a gate for
the first counter. If you change the pulse train to generate continuously or
only generate one pulse, you can run two counter tasks at the same time
without error."
In other words, generating finite pulses on CTR0 uses CTR1 as a gate which
also generates pulses, and vice-versa. This is why the transfer drum and
paper feed are both activated when either is controlled using N pulse
generation.
As a side note, the 6602 DAQ is only capable of operating two counters at a
time (whether for acquiring or generating signals, or both). Thus, if the DAQ
is instructed to perform N pulse generation that is all it can do because it
uses two counters.
SOLUTION:
Use non-paired counters or use continuous pulse generation on each counter in
a pair. Also look into purchasing another counter/timer DAQ card for access
to more counters (Jeff: “not necessary at this time”).
II) Use built-in i/o system (generally for safety, wiring, and determining nominal values)
On user interface, there is the ability to set pre-defined values for controllable variables in the
xerographic system such as velocities, bias, etc. These values can be stored in separate input .ini
files and the results of running the system under these settings can be saved in output files through
the user interface as well.
Sample of an input .ini file:
[Charging Station Parameters]
PC Velocity Across Coronode (mm/s)=110
Coronode Bias (v)=-650
Grid Bias (v)=-650
[Exposure Station Parameters]
Expose Time (s)=2
[Developer Station Parameters]
PC Velocity Across Developer (mm/s)=110
Toner Bias (v)=-525
[Pre-Transfer Station Parameters]
PC Velocity Across Pre-Transfer LEDs (mm/s)=110
[Transfer Station Parameters]
PC Velocity Across Transfer Drum (mm/s)=110
Number of Transfer Drum Rotations=3
Transfer Bias (v)=2000
Transfer Drum Velocity (mm/s)=110
Sample of an output .csv (excel) file: (Note: only a small portion of output shown here because it is
generally very large.
Time
(s)
PC Velocity
(mm/s)
0.1
34.272
0.2
84.481
0.3
110.772
0.4
110.772
0.5
110.772
0.6
110.772
0.7
110.772
0.8
110.772
0.9
110.772
1
110.772
1.1
110.772
1.2
110.772
1.3
110.772
1.4
110.772
1.5
110.772
1.6
110.772
1.7
110.772
1.8
110.772
1.9
110.772
2
110.772
2.1
110.772
2.2
110.772
2.3
110.772
2.4
110.772
2.5
110.772
2.6
110.772
2.7
110.772
2.8
110.772
2.9
110.772
3
110.772
3.1
110.772
3.2
110.772
3.3
110.772
3.4
110.772
3.5
110.772
3.6
0
3.7
0
Proposed Excel Macro Output:
120
PC Velocity (mm/s)
100
80
60
40
20
0
0
0.5
1
1.5
2
Time (sec)
2.5
3
3.5
4
Starting Point Values for General Testing (getting toner on paper)
For the purposes of this general experiment, we will be using the ranges of values given in the
engineering specs (for the settings that can be controlled):
Subsystem
Charging
Charging
Charging
Charging
Charging
Charging
Exposure
Exposure
Exposure
Exposure
Exposure
Exposure
Development
Development
Development
Development
Development
Development
Development
Development
Development
Development
Pre-Transfer
Erase
Pre-Transfer
Erase
Pre-Transfer
Erase
Pre-Transfer
Erase
Pre-Transfer
Erase
Parameter
Photoreceptor
Velocity
Coronode
Current
Grid Voltage
Spacing
Stray Light
Final Voltage
Lamp
Intensity
Expsore time
Spacing
Stray Light
Charged
Voltage
Exposed
Voltage
Bias
AC Voltage
AC Duty
Cycle
Mass on roll
Sleeve speed
Donor speed
Stray Light
Photoreceptor
Velocity
Exposed
Voltage
Developed
Mass
Lamp
Intensity
Spacing
Charged
Voltage
Photoreceptor
Velocity
Erased
Voltage
Recommended
Range
Subsystem
Output?
Units
Controllable?
mm/s
Y
80-120
N
μA
V
mm
erg
V
Y
Y
Y
Y
Y
1800
-650
1-2
Minimize
-650
N
N
N
N
Y
erg
s
mm
erg
Y
Y
Y
Y
1-2
2
<0.5
Minimize
N
N
N
N
V
Y
-650
N
V
V
kV
Y
Y
Y
-150
-525
1
Y
N
N
%
mg/cm2
mm/s
mm/s
erg
Y
Y
Y
Y
Y
50
30
130
130
Minimize
N
N
N
N
N
mm/s
Y
100
N
V
Y
-150
N
mg/cm2
Y
0.5
Y
erg
Y
4-5
N
mm
Y
25
N
V
Y
-650
N
mm/s
Y
100
N
V
Y
-50
Y
Transfer
Transfer
Transfer
Transfer
Transfer
Transfer
Transfer
Transfer
Transfer
Intermediate
Roll Bias
Photoreceptor
Velocity
Intermediate
Roll Velocity
Intermediate
Roll Normal
Force
Developed
Mass
Transfer Roll
Bias
Transfer Roll
Normal Force
Transferred
Mass on
Interm. Roll
Transferred
Mass
V
Y
2000
N
mm/s
Y
100
N
mm/s
Y
100
N
g/mm
Y
700
N
mg/cm2
Y
0.5
N
V
Y
-2000
N
g/mm
Y
700
N
mg/cm2
Y
0.45
N
mg/cm2
Y
0.45
Y
The purpose of performing this experiment is to first see if toner particles get on paper, and then once
that is achieved, performing this experiment repeatedly afterwards will be used to determine the
nominal value to achieve maximum quality of the image on paper.
Focused Needs: Hardware Specifications, Safety, Carriage Velocity Control
Testing the Quality of Enclosure Design:
This type of experiment will require two runs: one with our enclosure on and lights on with controllable
values as close to nominal as we can get at that time, and one with the lights turned off (to ensure
optimal lighting sightings). We will then use the ESVMs to determine the voltage after each of the first
two stations and see if there is either a statistically significant difference between the two and/or
patterns among the resulting readings in order to quantitatively measure the image quality both with
the enclosure and with the lights off. Other metrics that can be used to gauge image quality are the
mass of resulting toner on paper and line width of the image on paper.
Focused Needs: Functional Subsystems, Hardware Specifications
Determining Safety Limits of High Voltage Settings/Controls & Velocity of Carriage:
Given the engineering specs to guide our preliminary voltage and velocity settings, we will further test
the limits concerning safety issues by finding out the highest value(s) for each control that an operator
would ever need to set. Then starting from safer/lower values and building up iteratively we would
basically stress test the system to determine how high a voltage or how high a velocity a user should be
able to set which would then translate to hard-coded restrictions in the LabView component of the
project.
Focused Needs: Hardware Specifications, Ensure Safety, Carriage Velocity Control
Determining Optimal Photoreceptor Charge:
By varying coronode current (uA) and grid voltage (-V) through power supply controls either on
hardware side or through LabView once we integrate the system with the new DAQ, we can attempt to
narrow down values for the optimal photoreceptor charge/voltage after it passes over the coronode
that lends itself the best towards maximum image quality. We will use the ESVM placed at the end of
the charge station in order to measure the resulting voltage. As per our preliminary engineering specs,
we will begin testing with current set to 1800 uA and grid voltage at -650V and assess from there.
Focused Needs: Hardware Specifications
Optimizing Outputs of Photoreceptor Discharge:
By varying the time the photoreceptor carriage passes over the exposure station (seconds) and intensity
of exposure lamps (ergs), we can attempt to narrow down values for the optimal photoreceptor
discharge/exposed voltage for our system. The ESVM placed after the exposure station will be used to
measure the resulting voltage. Our initial setting for exposure time of the photoreceptor is two seconds
and 1-2 ergs for lamp intensity and we will iterate from there towards optimal exposure time.
Focused Needs: Hardware Specifications
Optimizing Photoreceptor Erase Voltage:
(***Contingent on obtaining another ESVM)
If we are able to get another ESVM to place after the pre-charge station, we will be able to start
optimizing the photoreceptor erase voltage (-V) through varying the relevant controls which are pretransfer lamp intensity (ergs) and distance between the lamp and the photoreceptor (mm). The initial
values for this testing will be 4-5 ergs for the lamp intensity and 25mm for the distance between the
lamp and the photoreceptor when it passes over it.
Focused Needs: Hardware Specifications
Usability Testing:
The interface should be useable by anyone of various different backgrounds and educational levels and
interests. As such, usability tests should be performed iteratively on our LabView interface by having
different people that don’t have any direct xerography experience to use a functioning version of the
project. Afterwards they will be surveyed and asked what they found difficult or what they liked. This
feedback will feed into future iterations of our front end and possibly back end of LabView.
Focused Needs: Ease of Use