In producing technical documentation, I will spend time on-site as much as is necessary to gather the facts that are pertinent to the assignment. I work closely with knowledgeable personnel to discern what issues need to be addressed and to gain a clear understanding of the technicalities involved.
This approach applies whether we are dealing with annual reports, press releases, or highly technical documentation such as maintenance manuals. Furthermore, I take care to write the final copy so that the intended audience will understand it clearly, without either being too technical or too simple.
I have selected two samples here of highly technical material in order to show the level of detail that we can attain. Both of these extracts are from large user manuals, the first from a software programming guide which was associated with a quality control scanning machine, and the second from a maintenance manual for machinery used to produce computer disks. The audiences for each manual were highly skilled technicians, already familiar with the processes and machinery involved.
Each of these manuals was well illustrated with diagrams and schematics, some produced by me and some scanned from draftsmen's diagrams. Each was delivered to the customer in final printed form, meeting ISO 9000 certification standards. (Copyright restrictions prohibit reproduction of artwork here, so only text is being presented.)
copyright 1999, Unilever Corporation
Operators are the different types of scanning operations which the Series II will perform. This section defines the theory Operators and describes each of the specific Operators offered by the Series II. For further information on when to use each Operator, see Appendix B.
Some Operators require specific reference points to function properly. For example, the Center Point Operator determines the center point between a newly defined window and another point on the package. This means that the designated scan starting point (such as upper left; see Windows, page 39) will be anchored to another point on the product. As the products pass through the Series II, any slight deviations of product or feature positioning will be compensated for, and the scan window will always fall on the same spot. The starting point references are as follows:
Same: The reference is that which has been previously taught; e.g., where:
A= Absolute
P= Package
F= Feature
Package: The reference is the center point between the First and Second Points, defined in Teach Package. (Hint: if you define a feature to locate the edge of the label on a bottle, you would reference that feature to the Package; the Series II would then determine the label's position in relation to the center point of the package.)
Absolute: The Operator is defined in reference to the upper left pixel of the camera monitor: row 0, column 0. (Hint: if your camera image is zoomed in on the product, and you have not determined the center of the Package by using Teach Package, use and Absolute reference point to determine a feature's position on the Product.)
Feature: The Operator is defined in reference to the results of a previously taught feature. (Hint: if two features need to be a specific distance apart, use a Features reference point to reference the second feature to the first.)
In the example at right, Feature 2 has a reference point of Absolute. This anchors it to the upper left corner of the camera monitor, shown in this figure by the diamon at pixel 0, 0. This reference point is best used when camera registration is accurate, and there is little shifting of product positioning. In this example, if the next toothpaste tube should be slightly to the left, the Series II will expect to find Feature 2 to the right of where it is here, because it references Feature 2 to a fixed position on the camera monitor.
In this example, Feature 2 is using a Package reference point. This anchors Feature 2 to the center point between the two package edges, which was found when scanning for First and Second Points. This is a good way of ensuring that Feature 2 is always in the same position on the toothpaste tube, as the Series II will always expect to find the Feature in the same place on the package, regardless where the package is on the camera monitor.
copyright 1998, Wescorp Inc.
2.11. Set Point Controller
2.11.1 A photo eye senses when there is no disk, one disk, more than one disk, or a damaged disk in the hub/burnish area. It does this by sensing voltage levels from light passed through the disk. If the voltage exceeds the high threshold, it senses that no disk is present. If the voltage drops below the low threshold, it senses that there are more than one disk present. As different media will have varying levels of translucence, it may be necessary to adjust the high and low thresholds of the set point controller. The following procedure and settings are recommendations and may need to be modified for different media. See Figure 10 for further information.
2.11.1.1 With Burnisher in the idle mode, place one disk on the locating pins in the hub assembly area.
2.11.1.2 Using the hand-held programmer, force on output 111. Using a digital voltmenter, measure the DC volts between pin 7 and pin 8 on the set point control (located inside the operator control panel).
2.11.1.3 Press the RESET button so that the disk can spin freely. Rotate the disk slowly by manually turning the hub. Note the voltage on the voltmeter; if the voltage shifts by 0.5 volts or more (due to media variance), place the disk so that the lowest reading is present.
2.11.1.4 Adjust the gain amplifier until the voltage between pins 7 and 8 is between 5.0 and 5.5 volts DC. (NOTE: this is a recommended range, and may need to be slightly different for different media.)
2.11.1.5 Push the STOP button (extending locating pins), and use the hand-held programmer to remove force on output 111. Insert a second disk on the locating pins and force on output 111 to clamp both disks to the hub. Note the voltage at pins 7 and 8.
2.11.1.6 Adjust the low threshold potentiometer until the voltage between pins 1 and 7 is 0.1 volts above the voltage read in the last step.
2.11.1.7 Remove the force on output 111, using the hand-held programmer, and push the RESET button to clear the hub area. Take another voltage reading between pins 7 and 8. Set the high threshold, read on pins 2 and 7, to 0.1 volts below the voltage read on pins 7 and 8 in step 2.11.1.5
All rights held by copyright owners; used by permission. No reproduction or use is authorized without written permission from Gregory C. Benoit and other copyright owners.