Case Studies
Print-Head Testing
The customer's task is to develop a system that is capable of driving and testing a prototype printhead. Because they work in R&D, requirements are constantly changing and therefore their optimal solution would be re-programmable - hence, their choice of the Gage CompuGen 3250.
The current version of the printhead requires two 16-bit data busses, as well as several control lines such as DataClock, Strobe, ModeSelection and End_of_Scanline. Thus, they have chosen a synchronous two-CompuGen 3250 board system (Master/Slave) as the basis for their system. Their next iteration includes an improvement in system speed obtained by doubling the data-bus width from 32-bits to 64-bits. This will be accomplished simply by reconfiguring to a three-CG3250 board system (Master/Slave/Slave).
Their application requires mimicking the control signals and data sent to a printer. For this, 16 control-signals and 32 data-lines are required. The control signals are essentially the same for each scanline, however the data (especially pictorials) are usually non-repetitive. Therefore, their plan was to use a CG3250-256k board to generate the control signals, and the CG3250-8M board to create the data signals. The 8M board enables a 12.5"x13.7" print-sample at a resolution of 600x2400dpi = 1.4MB (one byte per pixel). The task then becomes translating the image-file format (.bmp, .gif, .jpg) to the Gage signal-file format (.sig) for output. Currently, Master/ Slave Sets must be of the same memory size. Consequently, the customer ordered two CG3250-8M boards configured in Master/Slave mode.
Most of their testing only requires that they test repetitive data, or data that is the same for each printed scanline. This simplifies the task in that only one scanline of data needs to be programmed. The CG3250s are then configured to continuously loop the digital pattern while data and measurements are taken. This also minimizes the amount of memory required. In the future, they would like to extend their capabilities to be able to print full-page pictorial images using the CG3250.
GAGE'S SOLUTION
The advantage of the CompuGen-based system lies in its programmability. The customer can quickly make changes without burning EPROMs or reconfiguring FPGA (Gate Arrays). The only hardware investment made is an interface board that lies between the output of the CompuGen boards and the input to their printhead. This interface board buffers, and translates signals to the differential Low Voltage TTL (LVTTL) levels required by the printhead.
PRODUCT RECOMMENDED
2 (or 3) CompuGen 3250-8M
Master/Slave Multi-Card Upgrades for the CG3250s
External Clock Upgrades for the CG3250s
CG3250 Accessories:
Pleated-Foil Cable
BNC Breakout Board
Instrument Mainframe IM2020D (10xPCI, 8xISA slots)
CompuGen Digital Software Development Kit for Win 95/98/NT
This application note is provided "as is" without any warranties of any kind, either expressed or implied, including but not limited to the implied warranties of merchantability or fitness for a particular purpose. Gage Applied Technologies further does not warrant the accuracy and completeness of the material contained herein. Gage Applied Technologies may make changes to this material, or to the products described in it, at any time without notice.
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