PC24E and PC25E HIGH SPEED FOUR CHANNEL DIGITAL TO ANALOG CONVERTER BOARDS This Instruction Manual is supplied with the PC24E or PC25E to provide the user with sufficient information to utilise the product in a proper and efficient manner. The information contained has been reviewed and is believed to be accurate and reliable, however Amplicon Liveline Limited accepts no responsibility for any problems caused by errors or omissions. Specifications and instructions are subject to change without notice.
DECLARATION OF CONFORMITY AMPLICON LIVELINE LIMITED CENTENARY INDUSTRIAL ESTATE HOLLINGDEAN ROAD BRIGHTON BN2 4AW UK We declare that the product(s) described in this Instruction Manual are manufactured by Amplicon Liveline Limited and perform in conformity with the following standards or standardisation documents: Electro Magnetic Compatibility (EMC): EMC Directive LVD Directive CE Directive 89/336/EEC 73/23/EEC 93/68/EEC Jim Hicks, I.
PC24E AND PC25E HIGH SPEED FOUR CHANNEL D to A CONVERTER BOARD CONTENTS PARAGRAPH SUBJECT PAGE 1. 1.1 1.2 1.3 GENERAL INFORMATION General Description What the Package Contains Features 2. 2.1 2.2 2.3 2.4 2.5 2.5.1 2.5.2 2.5.3 2.5.4 2.5.5 2.5.6 2.5.7 2.5.8 2.5.
LIST OF FIGURES FIGURE TITLE PAGE FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 FIGURE 9 FIGURE 10 FIGURE 11 FIGURE 12 FIGURE 13 FIGURE 14 FIGURE 15 FIGURE 16 SW1 DIL SWITCH SELECTION OF BASE ADDRESS IRQ LEVEL SELECTION CLOCK JUMPER SELECTION GENERAL PURPOSE CLOCK JUMPER SELECTION J15 WAIT STATE SETTINGS DAC LOADING MODES PC24E OUTPUT VOLTAGE RANGES CONNECTOR PL1 PIN DESIGNATIONS MAIN PC BUS BACKPLANE CONNECTOR PIN ASSIGNMENTS INPUT/OUTPUT ADDRESS SPACE BIPOLAR TRANSFER FUNCTIO
PC24E AND PC25E HIGH SPEED FOUR CHANNEL D to A CONVERTERS 1. 1.1 GENERAL INFORMATION General Description The PC24E and PC25E are four channel, 12-bit digital to analog converter cards for installation in an IBM PC/XT/AT, PS2/30 or compatible computer. The PC24E is a four channel analog voltage output card with individual jumper selectable output ranges of 0 to +2.5v, ± 2.5v or 0 to +10v, ±10v. The PC25E is a four channel analog current output card, sourcing 4 - 20 mA between current output and ground.
1.3 Features • Four 12-bit digital to analog converters. • Unipolar or Bipolar operation in four user selectable ranges (PC24E only). • 4-20mA output (PC25E only). • On-board 1MHz frequency reference that can be disabled for ultra quiet operation. • Two triggering modes. • Flexible addressing. • On-board programmable wait state generator for compatibility with faster machines. 2. 2.
2.4 Installing the Software onto a Fixed Hard Disk To install the software onto your hard disk, insert the diskette into drive A and select File|Run... from the Windows Program Manager, or if you are using Windows 95 select Run... from the Start menu. In the dialogue box that follows, type A:\SETUP The PC24E/25E software setup program will now run. Follow the instructions given on the screen to complete the installation.
Figure 1 SW1 DIL SWITCH SELECTION OF BASE ADDRESS 2.5.2 Interrupt Request Selection To accurately time DAC output waveforms, a programmable clock interrupts the host computer on a selected IRQ level at the required intervals. 2.5.2.1 Jumper Setting of IRQ Level An interrupt level must be chosen that is not otherwise used in the system.
the output of counter 1, and in the 'DOWN' position, counter 1 output is available at the output connector, PL1 pin 4. For counter 2 to generate a hardware interrupt, it must be cascaded with counter 1 and counter 0. The various configurations of jumpers J10, 11 and 12 for internal interrupt generation are shown in figure 3.
OUT2 J20 PL1-3 GAT2 J16 PL1-1 CLK2 J18 PL1-14 UP OUT1 PL1-4 J11 DN GAT1 J17 PL1-2 CLK1 J19 PL1-15 UP OUT0 J12 PL1-16 DN GAT0 +5V CLK0 1MHz J10 IRQ 2 1 0 Figure 4 GENERAL PURPOSE CLOCK JUMPER SELECTION 2.5.3 Wait State Generator Setting (Option) The PC24E/PC25E has an option to incorporate an on-board wait state generator (QA19) to enable it to operate reliably in a wide range of PC/XT/AT and ISA machines.
Nº OF WAIT STATES EXPANSION BUS SPEED J15 JUMPER SETTING 0 1 2 3 Up to 8 MHz 8 to 10 MHz 10 to 12 MHz 12 MHz and above No jumper 3 4 5 Figure 5 J15 Wait State Settings 2.5.4 DAC Loading Mode Each Digital to Analog Converter (DAC) has twelve bits resolution and the data word is right justified and loaded sequentially in two bytes, the least significant byte (LSB) of eight bits and the most significant byte (MSB) of four active bits.
The PC24E is supplied with all four channels set up and calibrated for +10V unipolar operation. If the range is changed, the output voltages should be checked and recalibrated if necessary using the procedure described in paragraph 2.5.8. Jumper J3 is available on the PC25E, but would normally remain set at the default position of 10V. However, if special scaling of the PC25E for low current outputs is required, then jumper J3 may be positioned at 2.5V.
2.5.7 Testing the PC24E/25E When installation is complete, the PC24E/25E can be tested by loading and running the programs on the supplied demonstration disk and measuring the fixed outputs using a digital multimeter or viewing the sine wave outputs on an oscilloscope. See section 4. 2.5.8 Calibrating the PC24E When the output voltage range of any channel is changed by jumper selection, the calibration should be checked using the following procedure. 1. UniPolar Calibration 1.
2.5 Enter the data value 4095 which gives a negative full scale output voltage of –2.500 or –10.000 as selected by J3. Press any key twice to load the DACs. 2.6 Adjust the appropriate trimmer potentiometer to give exactly –2.500V or –10.000V according to the setting of J3. The potentiometers located at the top of the board are adjusted according to the table below. 2.7 Select item 3 from the menu. ' Write a value to all four DACs'. 2.
3. 3.1 ELECTRICAL CONNECTIONS User Connections All user input/output connections are via a 25 way D type connector PL1. The pinouts for this connector are shown in figure 8.
3.3 Main I/O Bus Backplane Connections Connection to the computer is made through the 62 pin I/O bus connector (Pins B1 and A1 are at the bracket end of the board). Pin connections are shown in figure 9. For further information please consult the technical reference manual for the host computer.
4. PROGRAMMING THE PC24E/25E The PC24E/PC25E is supplied with a 31/2 inch diskette containing Windows DLLs with Microsoft Visual Basic example programs, and a Borland Turbo Pascal DOS demonstration program. See Section 2.4 to find out how to install the software onto your hard disk. 4.
3. Write a value to all DACs. 4. Output a Sine wave to one DAC. 5. Output a Sine wave to all DACs. 6. Exit. Option 1 need only be chosen if a base address other than the factory set 300 hex has been set up on the board. Enter a number 2 to 4 to choose the required output(s) and follow the on-screen instructions. Note: All values are input as decimal numbers, which can take any value from 0 to 4095. 4.
4.4 Programming the AD7548 Digital to Analog Converter The PC24E/25E has been designed for straightforward user programming of the four DAC chips. Being 12 bit DACs they have to be loaded by sending the output data as two bytes to the appropriate DAC register addresses as shown in figure 10 above. Note that the data must be right justified and the order of sending the two bytes must be as selected by jumpers J6 to J9.
1LSB=FS/4095 + FS (+10V or +2.5V or 20mA) Unipolar Transfer Function O U T P U T Half Scale V or I Zero (0V or 4mA) 000h 7FFh FFFh DIGITAL INPUT CODES Figure 12 UNIPOLAR TRANSFER FUNCTION 4.4 Programming the 82C53 Counter/Timer Full details of the 82C53 Counter/Timer and its various programming modes are given in the appendix.
0 1 1 1 0 1 1 0 = 76 hex. This value has to be loaded to the control register whose address is Base Address + 0B. Assuming that the board address is 0300, the BASIC statement OUT &H030B, &H76 will load the control register with 76 hex. The value of the count has now to be loaded to the counter. The address of Counter 1 is base address + 09 which, in our example would be 0309.
5. 5.1 TECHNICAL SPECIFICATIONS Electrical Specification All Analog Outputs Number of Channels Resolution Relative Accuracy Differential Nonlinearity Settling time to 0.05% FSR Reference Stability 4 12 bits ±1 LSBit ±1 LSBit 5µSec (Typ) 15 ppm/°C (Typ) Voltage Outputs (PC24E) Voltage Ranges Max. O/P Current (Source/Sink) Unipolar 2.5 or 10V Bipolar ±2.
Figure 13 PC24E PRINTED CIRCUIT BOARD LAYOUT PC24E/25E Page 23
Figure 14 PC24E CIRCUIT DIAGRAM PC24E/25E Page 24
Figure 15 PC25E PRINTED CIRCUIT BOARD LAYOUT PC24E/25E Page 25
Figure 16 PC25E CIRCUIT DIAGRAM PC24E/25E Page 26
6.
