GTCO CalComp CR-1212 User manual

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Chapter 1
Chapter 2
Chapter 3
Chapter 4
What is the CR 1212 and How Does It Work?
Section A: What is the CR 1212?
Section B: How the CR 1212 Works
Section C: Commands: Controlling the Tablet’s Operation
Section D: Alternative Configurations
Assembly and Installation
Interfacing with the Host
Section A: Hardware Interfaces
Section B: Baud Rate
Section C: Communication Protocols
Section D: Report Formats
Operating Characteristics and Functions
Section A: Controlling the Report Flow
Point Mode
Remote Request Mode
Stream Mode
Switch Stream Mode
Report Rate
Increment Mode
Section B: Setting the Resolution
Resolution, Predefined
Resolution, Definable (Set X, Y Scale)
Section C: Other Functions
Bit Pad Configuration
Origin
Relative Coordinates (Delta Mode)
Reset (to Default Operating Characteristics)
Send Configuration
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Chapter 5
Chapter 6
Chapter 7
Chapter 8
Appendix A
Appendix B
Tablet Beep
Transmission Control
Section D: Reserved Commands
Guidelines for Writing a Device Driver
Using the CR 1212
Checking the Graphics Tablet
Section A: Tablet Calibration
Section B: Power (and Proximity) Light
Section C: A Quick Functional Check
Section D: Diagnostic Functions
Echo
Self-Test
Operating Environment, Care and Service
Section A: Operating Environment
Section B: Service
Section C: Care and Cleaning
Section D: Changing the Stylus Refill
Specifications
ASCII Conversion Chart
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Chapter 1: What is the CR 1212 and How Does It Work?
Section A: What is the CR 1212?
CR 1212 is a graphics tablet that acts as an input device. It allows for the translation of
graphic information into digital, suitable for a digital device such as a computer.
Steering a computer screen pointer
Selecting locations on menus
Drawing and tracing
The components required for a functional CR 1212 are:
Tablet
Stylus or cursor
Interface cable
Power source
The tablet is similar to a drawing board. The stylus and cursor are handheld devices that
are used for pointing or drawing on the tablet. The interface cable connects the graphics
tablet to the host (computer).

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Section B: How the CR 1212 Works
CR 1212 translates the stylus/cursor position on the tablet into digital information and
communicates it to the host. The stylus/cursor position is expressed as an X, Y coordinate
pair. One coordinate pair is a report.
Valid reports can only be collected when the stylus/cursor is in the tablet’s active area and
in proximity:
Active area is a 12-inch square area inside the groove on the tablet surface.
Proximity is the maximum distance above the active area that the stylus/cursor can
be held and report a valid position. It’s approximately ½ inches, which means the
stylus/cursor and tablet do not need to be in direct contact with each other to issue
reports. There still can be up to a ½ inch of material (drawings, photos, etc.)
between the tablet and stylus/cursor, allowing it to issue reports.
The active area and proximity, in effect, establish a three-dimensional volume within which
the stylus/cursor can issue valid reports. Reports issued from outside of this volume are
out-of-prox and, therefore, do not represent the current position of the stylus/cursor.
Reports are measured in counts of resolution. Resolution is the fineness of detail that the
tablet can distinguish. It’s expressed in lines per inch (lpi) or lines per millimeter (lpmm).
This is slightly misleading, however. Resolution should be expressed in “bands per …” or
“lanes per …” because these lines have perceivable width at lower resolution settings.
The higher the resolution, e.g. 100 lpi or 200 lpi, the narrower the bands of resolution
become. Eventually, the bands become so narrow that they are easier to conceptualize as
lines of no measurable width.

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As previously stated, reports are measured in counts of resolution. As shown below, each
square is one count of resolution. The tablet reports the same coordinates for any point
within the square.
With different resolution settings, you can receive different reports for the same tablet
location. In the illustration below, points A and B are the same physical locations on the
tablet, but their coordinates are different because of the resolution setting.

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Reports are in absolute or relative coordinates. Absolute coordinates are coordinates
measured from the tablet’s origin (0, 0). Relative coordinates are measured relative to the
last report location. In the illustration above, point B is issued after point A. Therefore, in
relative coordinates, point B is measured relative to point A.
The tablet defaults to absolute coordinates. However, you can change to relative
coordinates with the Relative Coordinates command, described in Chapter 4.
Section C –Commands: Controlling the Tablet’s Operation
Control the CR 1212’s operating characteristics, functions and diagnostics with commands
from the host. This book represents the commands in ASCII. For convenience, an ASCII
conversion chart appears in Appendix B.
The tablet accepts commands from the host at any rate, except as follows:
After turning on the tablet, wait approximately 300 milliseconds before sending
commands.
Commands that require a tablet response: If you send a command to the tablet that
requires a response, the tablet does so within two milliseconds. Wait until the host
receives the entire response before issuing another command to the tablet.
Definable Resolution (Set X, Y Scale): After issuing the Definable Resolution
command, wait for at least 0.5 milliseconds before issuing another command to the
tablet.
Section D: Alternative Configurations
CR 1212 comes in three operational configurations: Bit Pad One, Bit Pad Two and CR. The
standard configuration is Bit Pad One. The other configurations are special orders.

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Chapter 2: Assembly and Installation
The CR 1212 package should include the following:
Tablet
Stylus or cursor
Interface cable
CR 1212 Graphics Tablet User’s Guide
To assemble and install CR 1212:
1. Connect the stylus/cursor to the tablet.
2. Attach the tablet to the host and power source.
3. Turn on the tablet.
NOTE: Always have the computer and tablet power off when attaching or detaching any
part of the CR 1212. If the power is on, nothing serious happens to the CR 1212, but it
could have the potential to corrupt the file being worked on or cause the computer to
malfunction.
Installing CR 1212 Graphics Tablet
1. Plug the stylus/cursor into the phone socket on the right-hand edge of the tablet.

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The cursor and stylus are interchangeable. However, before changing from one to the
other, turn off the tablet. (This allows the tablet’s internal software to re-initialize for each
device.)
2. Plug the 8-pin phone connector on the interface cable into the tablet.
3. Connect the 25-pin D connector of the interface cable into the host communications
port.

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4. Plug the power supply barrel connector into the interface cable’s D connector.
5. Plug the power supply into a grounded electrical outlet. Use only a CR 1212 power
supply. Substituting a different power supply could permanently damage the
graphics tablet.
6. Turn the tablet on.
Turn the power (ON/OFF) switch on. The tablet calibrates itself. This takes approximately
three seconds and once the calibration is complete, the tablet beeps.
The power light is lit when the tablet is on. It’s also a proximity indicator that remains lit
when the stylus/cursor is in-prox. It blinks when the stylus/cursor is out-of-prox. If the
light blinks when the stylus/cursor is in-prox, then the tablet is malfunctioning. Turn it off
for 10 or 20 seconds, and then turn it on again. If it fails again, have it serviced.

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Chapter 3: Interfacing with the Host
For successful communication between the CR 1212 and its host, they must have the same
hardware interface, baud rate, communications protocol and report format.
Section A: Hardware Interface
The hardware interface for the CR 1212 is an RS-232C with a 25-pin D connector. The pin
assignments are listed below.
RS-232C Interface: 25-Pin D Connector Pin Assignments
The computer must have an RS-232C communications port terminated with a 25-pin male
D connector that is configured as DTE (Data Terminal Equipment).
NOTE: If the computer has a different connector, contact your GTCO CalComp by Turning
Technologies representative for information about adapter cables.
The CR 1212 complies with standard signal levels for data transmission:

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RS-232C Signal Levels
NOTE: The source is the EIA Standard RS-232C: Interface between Data Terminal
Equipment and Data Communication Equipment Employing Serial Binary Data
Interchange, by the Engineering Department of the Electronics Industries Association
(Washington, D.C.: EIA, 1969).
Section B: Baud Rate
The CR 1212 is available with 9600 baud or Autobaud. The standard setting is 9600 baud,
unless Autobaud is specifically ordered.
Autobaud automatically matches the tablet baud rate to the host baud rate. The tablet
supports 9600, 4800, 2400 and 1200 baud. With Autobaud, you must send an ASCII space
(SP) to the tablet just after starting it. The tablet uses this character to identify the host
baud rate. The tablet then sets its baud rate and issues an ASCII acknowledge (ACK) to the
host.
Section C: Communication Protocols
The CR 1212 communication protocols are:

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Section D: Report Formats
The CR 1212 has one of the following report formats:
Bit Pad One-compatible format (default)
Bit Pad Two-compatible format
CR format (similar to MM packed binary format)
Bit Pad One- or Two-compatible format for Relative Coordinates (Delta Mode)
CR format for Relative Coordinates (similar to MM packed binary format for Delta
Mode)
The report formats are in (packed) binary. The reports are in counts of resolution, not in
inches or millimeters.
Bit Pad One-Compatible Report Format

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Bit Pad Two-Compatible Report Format
CR Report Format

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Bit Pad One- or Two-compatible format for Relative Coordinates
CR Format for Relative Coordinates
Key:
LSB is the least significant bit. MSB is the most significant bit.
Fa, Fb, Fc and Fd are the flag bits. They identify the status of the stylus tip and
cursor buttons:

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*Output for Bit Pad One or Two configurations using absolute coordinates.
**Output for Bit Pad One or Two configurations using relative coordinates.
Sx and Sy are the X and Y coordinate signs. 1 is positive and 0 is negative.
PR is the proximity bit. 0 is in-prox and 1 is out-of-prox.
PH is the phasing bit, which is always 1.
X0, X1, etc. and Y0, Y1, etc. are the X and Y coordinate bits.

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Chapter 4: Operating Characteristics and Functions
The CR 1212 includes a variety of operating characteristics and functions that can be
controlled with commands from the host. For example, define:
Report flow
Tablet resolution
Tablet origin location
The tablet accepts commands from the host at any rate, except in a few situations. So that
the CR 1212 is operable upon arrival at your facility, it is set to predefined default settings.
The unit defaults to these settings each time you turn on the tablet or issue the Reset
command. A summary of the defaults appear in the Reset command section and in
Appendix B.
Section A: Controlling the Report Flow
The primary functions that control the report flow are Point, Remote Request, Stream and
Switch Stream modes. The secondary functions are Report Rate and Increment Mode.
Bit Pad One configurations: Each time the tablet is turned on or issues the Reset
command, it defaults to Stream Mode.
CR and Bit Pad Two configurations: Each time the tablet is turned on or issues the
Reset command, it defaults to Remote Request Mode.
Bit Pad One reports have no proximity bit. CR and Bit Pad Two reports have a
proximity bit.
Each report has flag bits. These bits identify the stylus/cursor buttons that were
activated when the report was issued.
There is a distinction between scanned reports and issued reports. The tablet reads
the stylus/cursor location 110 times each second. It stores the scanned reports in
an internal buffer. Although the tablet scans continuously, it only issues reports to
the host as dictated by the selected mode, such as Point Mode. The reports sent to
the host are called issue reports.

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A report issued when the stylus/cursor is out-of-prox is always the last in-prox scanned
report. Because the last scanned report may or may not be the last issued report, their
values could be different. You may find this occurring when collecting reports at very slow
rates.
Point Mode
In Point Mode, the graphics tablet issues one report when pressing a stylus/cursor button
and another when releasing it. (The tip of the stylus is its “button”.) If the stylus/cursor is
moved between the time the button is pressed and time it’s released, the reports will be
different. If the stylus/cursor is out-of-prox, the tablet issues the last in-prox scanned
report.
Remote Request Mode
In Remote Request Mode, the tablet issues one report each time the host sends a trigger
command. Issue the mode command once. Thereafter, send only a trigger command for
each report. After initiating Remote Request Mode, the tablet issues the report resulting
from the first trigger within two milliseconds. The tablet can issue subsequent reports up
to 110 rps (reports per second).
When the stylus/cursor is out-of-prox, the tablet issues the last in-prox scanned report
each time it receives a trigger.

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Stream Mode
In Stream Mode, the graphics tablet issues reports continuously, whether a stylus/cursor
button is pressed or not. The Report Rate, described below, controls the number of
reports issued per second.
When moving the stylus/cursor out-of-prox, the tablet issues the last in-prox scanned
report three or four times before it stops transmitting.
Switch Stream Mode
In Switch Stream Mode, the graphics tablet issues report continuously while pressing a
stylus/cursor button. The Report Rate, described below, controls the number of reports
issued per second. When releasing the button, the tablet issues an additional report. This
report is the last scanned report, but its flag bit is 0 (zero).
If the stylus/cursor is out-of-prox when pressing a button, the last in-prox scanned report is
issued continuously.

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Report Rate
The Report Rate function is an adjunct to Stream and Switch Stream modes. Use Report
Rate to define the number of reports the tablet issues each second. Each time the tablet is
turned on or issues a Reset command, the report rate defaults to 110 or 72 rps, depending
on the hardware configuration.
By their very nature, low baud rates limit the report rate. Therefore, follow these
recommendations:
No higher than 36 rps, when using 2400 baud
No higher than 18 rps, when using 1200 baud
Increment Mode
Command Sequence: <mode command><increment value>
Increment mode is an adjunct to Point, Remote Request, Stream and Switch Stream modes.
(It is particularly useful for reducing data output.) In Increment Mode, the unit sends a
report only when the stylus/cursor has traveled a minimum distance in the X or Y direction.
This minimum distance is the increment. It applies to both axes and is measured in counts
(of resolution).

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NOTE: When using Increment Mode, it’s recommended to use a resolution setting of 50 lpi
or higher.
How Increment Mode Works
The last report issued becomes the center of an imaginary square. The square’s sides
measure twice the increment value. The stylus/cursor can move anywhere inside the
imaginary square without the tablet issuing a report. When the stylus/cursor touches the
square, the increment is met and the tablet transmits a report. This point becomes the
center of a new imaginary square. The process repeats.
The following illustration shows the imaginary square created around a report point. The
increment is five.
The following example shows the reports issued as the stylus/cursor travels across the
tablet. The increment is ten. We have assumed that the first point collected is the origin (0,
0).