PC27E LOW COST 16 CHANNEL 12 BIT A/D CONVERTER BOARD This Instruction Manual is supplied with the PC27E 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: EMC Directive LVD Directive CE Directive 89/336/EEC 73/23/EEC 93/68/EEC Jim Hicks, I.
MODEL PC27E 16 CHANNEL 12-BIT A/D BOARD LIST OF CONTENTS PARA SUBJECT PAGE 1 1.1 1.2 GENERAL INFORMATION General Description Features 5 5 5 2 2.1 2.2 2.3 2.4 2.5 GETTING STARTED Installing the PC27E Requirements to Run the Software Backing up the Software Installing the Software on a Fixed Hard Disk DASH 27 Optional Software for the PC27E 6 6 6 6 7 7 3 SPECIFICATIONS 8 4 4.1 4.1.1 4.1.2 4.2 4.3 4.4 4.4.1 4.4.2 4.5 4.6 4.6.
FIGURE TITLE PAGE 1 2 3 4 5 6 7 8 SW1 D.I.
PC27E 16 CHANNEL 12 BIT DATA ACQUISITION BOARD 1. General Information 1.1 General Description The PC27E is a half sized plug in board which provides 16 channels of 12 bit, high speed analog to digital conversion. Integral sample and hold circuitry ensures stability during the conversion process. The PC27E board can be installed in the IBM PC/XT/AT, PS2 Model 30 and compatible computers.
2. GETTING STARTED The PC27E is supplied complete with Windows DLLs with Visual Basic example programs, and demonstration software written in Borland Turbo Pascal. The source code for the Turbo Pascal program is supplied and is compatible with version 4 and above. A copy of the language will be needed if the user wishes to edit the code. 2.1 Installing the PC27E Board ALWAYS SWITCH OFF THE POWER BEFORE INSTALLING OR REMOVING A DEVICE.
2.4 Installing the Software on 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 PC27E software setup program will now run. Follow the instructions given on the screen to complete the installation. See Section 6 ‘PROGRAMMING' for details on running the software. 2.
3. Specifications Size of board 154mm x 100mm typically Typical Conversion time (including sample/hold settling time) Page 8 10µs Converter accuracy 12 bits + 1/2 LSB input ranges: Bipolar ± 2.0 Volts ± 4.0 Volts Unipolar 0 to + 4.0 Volts Input Impedance >100MΩ per channel Multiplexer plus input amp settling time <10µS. Cross talk between any 2 channels (at 1 MHz) better than - 50dB Oscillator accuracy ±0.3% Oscillator stability ±0.
4. USER SETTINGS 4.1 Board Base Address The PC27E can have its base address situated within the range Hex000 to HexFF0. This feature provides the flexibility to avoid any contention in I/O mapping that may arise with some clones and allows the use of multiple cards fitted in the PC expansion slots. 4.1.1 Factory Setting The board’s base address is set at the factory to be Hex300. 4.1.
& ' ' ' ( ! ' !( )% )% #" * +,% - !3 !( )% )% #" * . +,% - !3 % #% / 01 # . 0 !3 ) %. # $% !3 . #( / )0% # !3 . #( / )0% # !3 !3 . #( / )0% # . #(/ )0% # / 0%# 2 #" !3 TABLE 1 ADDRESS SPACE FUNCTIONS 4.3 Interrupt Request Level Selection There are six Interrupt Request levels available on the PC27E, IRQ2 - IRQ7 with IRQ2 having highest priority and IRQ7 the lowest priority.
4.4.2 Frequency Measurements A simple Frequency Counter can be implemented using the external frequency output on connector SK1 pin 1. The output of Counter 0 is inverted by QA12-B, and then fed to the gate of counter 2 by positioning jumper J7 to /OUT0 (upper position). Therefore Counter 0 controls the gate of Counter 2 and, if Counter 0 is programmed for Mode 2 (terminal count), a fixed-length gate pulse can be created for Counter 2.
4.6 Input Voltage Range Setting The analog input voltage range can be set by the position of jumper J1. Table 3 shows the settings for the PC27E. J1 JUMPER POSITION UP BP No Jumper INPUT VOLTAGE RANGE PC27 0 to +4v -2 to +2v -4 to +4v TABLE 3 ANALOG INPUT VOLTAGE RANGE SETTINGS 4.6.1 Input Attenuators Although the PC27E has pre-defined input ranges, these can be modified on a channel by channel basis to allow higher or intermediate input voltages to be handled.
Channel Nº Input Pin SK1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Attenuator Resistor Positions Input Ground RN2 - A RN2 - B RN2 - C RN2 - D RN2 - E RN2 - F RN2 - G RN2 - H RN3 - A RN3 - B RN3 - C RN3 - D RN3 - E RN3 - F RN3 - G RN3 - H RN4 pin 2 RN4 pin 3 RN4 pin 4 RN4 pin 5 RN4 pin 6 RN4 pin 7 RN4 pin 8 RN4 pin 9 RN5 pin 9 RN5 pin 8 RN5 pin 7 RN5 pin 6 RN5 pin 5 RN5 pin 4 RN5 pin 3 RN5 pin 2 For example, to obtain a range of ±25 volts on analog input channel 0,
5. ELECTRICAL CONNECTIONS 5.1 User Connections Inputs and Outputs to the PC27E are connected via a 37-way D socket on the PC27E card mounting bracket and marked SK1. Be careful to observe pin numbering.
5.3 Main I/O Bus Backplane Connections Connection to the computer is made through the I/O channel main bus. The pin designations are shown in Figure 4, but for further information please consult the technical reference manual for the host computer.
6. PROGRAMMING The PC27E 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. 6.
6.3 7. Frequency Counter 8. EXIT to DOS Copyright The software on the demonstration disk is copyright Amplicon Liveline Ltd. Any user who has purchased a PC27E may use the software, or any part of it, for use in his own programs, or for resale when delivered with a PC27E. 6.4 Programming the 82C53 Counter/Timers The three counter/timers of the 82C53 can be independently programmed to operate in any one of six modes. These are: 1. Mode 0: Interrupt on Terminal Count. 2.
Example 1 To select Counter 1 to Mode 3, loading/reading low order byte followed by high order byte in binary, the control word is: 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 + 07. Assuming that the board base address is 0300, the following BASICA or QuickBASIC statement will load the control register with 76 hex. OUT &H0307, &H76 The value of the count has now to be loaded to the counter.
The 12 bit data word is not coded in pure binary, but in a form of 2s complement where the most significant bit is inverted. The transfer functions for bipolar and unipolar operation are given in figure 5. N.B. Under software sampling it is not possible to detect the status of each sample, so the user must insert a delay between starting the conversion and reading the first byte, typically >10µs.
6.6.2 Aliasing Never try to sample a signal at a rate less than or equal to twice the signal frequency. Otherwise distortion known as aliasing will arise where the frequency of the sample data will appear to be much less. Aliasing is illustrated in the following diagram. &4 ! ! & @ ! ! ! 6.6.3 Inherent Offset in ±4 Volt Bipolar Mode There is no facility to adjust the offset to zero in ±4 volts, bipolar mode.
6.7.2 6.7.3 5. Ensure jumpers J1 to J7 are correctly positioned according to the table on the screen. 6. Connect a precision voltage source between SK1 Pin 4 (positive) and Pin 22 (negative), and ground the unused channels by connecting SK1 Pin 5 to Pin 23, Pin 6 to Pin 24, Pin 7 to Pin 25,..... Pin 19 to Pin 37. 7. Set the voltage source to +0.97mV and adjust RV2 until data reading is 2048-2049. 8. Set the voltage source to +3.999 and adjust RV1 until data reading is 2046-2047. 9.
7. Set the voltage source to +3.998 and adjust RV1 until the data reading on the screen is 2046/2047. 8. Set the voltage source to -3.988 and check the data reading on the screen is 2048/2049. (N.B No offset adjustment in Bipolar ±4v - see 6.5.3). 'B / 1 'B % .% & / ' ! / ! % / 7 ' ' ! ! & !' C ! ! 4 ' .% /:! ! ! &4 ' ! ! ! 4 ) %.
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