DIGIMETRIX PC-ADC-12B 8V/D
ANALOG-DIGITAL-ANALOG CONVERTER BOARD
FOR IBM° PC/XT/AT / PS 30 OR COMPATIBLE
FEATURES
* 8 single channels of analog input ± 5V, +5V, 4-20 mA.
* Resolution : 12 bits, conversion time 25 µS (or 8 µS).
* Synchronisation for external lines, software, timer.
* 24 TTL digital Input/Output.
* 2 analog outputs from ± 0.5 to ± 10V.
* Resolution : 12 bits.
* Four programmable interrupt levels (IRQ 3, 4, 5, 7).
APPLICATIONS
* Data acquisition and data processing.
* Sensor interface with voltage-current analog ouputs.
* Command and regulation of automations.
* Logic OPTO22 interface, relay etc.
INTRODUCTION
The board PC-ADC-12B 8V/D is composed by an analog-digital conversion module associated to a logic input/ouput interface and a timer 8254. The module of two channels of a 12 bits digital/analog conversion is also implemented (/D).
Description of the different functions :
1) Analog-Digital interface :
It allows to measure up to eight signals in voltage o current. For the current signals a predrilled zone is located between the input connector P1 and the input multiplexor in order to enable the connection of a resistance between the signal and the 0 Volt on the desired input. The input full scale is switchable by jumpers. These signals are converted in 12 bits digital words on the input/output bus of your computer by means of a successive approximation con-verter. The triggering of the conversions may be done by software (B+2 address), by the timer 8254 to obtain precise sampling rates or by external signal for a synchronisation with an exter-nal system.
With the automatic incrementation of the channels, the timer and the interrupt trigge-ring at the end of a conversion you don't have to lock your PC in test at the end of the conver-sion or switching of the channels. You just have to keep the result in the interrupt routine.
2) Digital-Analog interface (/D option) :
Two independent channels of analog output are available on the connector P1. An offset potentiometer for each channel allows to adjust the 0 V with precision. A potentiometer of full scale enables to adjust it either from ± 0.5 to ± 10V in bipolar mode, either from 0 to 0.5V and from 0.5 to 10V in unipolar mode. The converter resolution is of 12 bits with a con-version time of 1.5 µS.
3) TTL input/output interface :
24 TTL channels are available on a HE10 50 pins connector (P2) for flat ribbon cable. They come from a 8255 of Intel. The line direction (input or output) is programmable by 8 bits ports (except for the port C in 2x4). The TTL ports are marked A, B and C.
4) Timer module :
The timer module uses a timer 8254 of Intel. A basic clock is available on the board : oscillator of 4 Mhz. A jumper zone enables to cascade the counters to allow the triggering of the interrupts or the triggering of the conversion.
5) Other :
* Swichable addressing by blocks of 16 addresses in the I/O space. IBM 8 bits bus.
* Size : 26 x 10 cm.
6) Programmation :
A complete example in C is listed in the handbook delivered with the board.
A library under DOS or Windows is available for the board interface. Here are some commands of functions :
AIN() : AD channel reading ; AOUT() : DA channel writing ; DIN() : logic channel reading ; DOUT() : logic channel writing etc.
TECHNICAL SPECIFICATIONS
ANALOG-DIGITAL INTERFACE :
* 8 single channels.
* Resolution : 12 bits (4096 points).
* Input scale : ± 5V, 5V.
* Possibility of an automatic incrementation of the channels.
* Input impedance : 10 Gigaohms / 3pF.
* Protection : up to 100V / mS.
* Conversion time : 25 µS (8 µS in option).
* Precision : 12 bits +/- 1 LSB.
* Digital coding : binary.
* Conversion triggered by : software, timer or external signal (TTL).
DIGITAL-ANALOG INTERFACE (/D) :
* Resolution : 12 bits (4096 points).
* 2 independent output channels.
* Output scales adjustable by potentiometer : from ± 0.5V to 10V, from 0 to 0.5V, from 0.5V to 10V.
* Settling time : 1.5 µS (10V impulse).
INPUT/OUTPUT INTERFACE :
* External control : one line in output on P1 (PC1).
* TTL channels : 24 lines (ports A, B, C) on HE10 50 pins connector.
INTERRUPTS :
* Four programmable interrupt levels (IRQ 3, 4, 5, 7).
* An interrupt can be generated by : a TTL external line, at the end of the conversion, timer.
WIRING :
AD and DA interface : female DB 37 points connector.
I/O TTL interface : male HE10 50 points connectors.
Connectors P2 :
PXX = TTL line + 5V = PC feeding 5V.
GND = 0 V TTL signals.
INFORMATION TO ORDER
PC-ADC-12B 8V : Board without the doble digital/analog converter.
PC-ADC-12B 8V /D : Board with the doble digital/analog converter.
Option /8 : convertion time option of 8 µS for the A/D converter.
The board is delivered with a complete handbook and a list of the corresponding software.
° Registred trademark of International Business Machine.
This data sheet information are communicated under Digimétrie's international sale and service general conditions.
Digimétrie : 30 A, rue E. Renan F-66000 Perpignan FRANCE
Tel : (33)04.68.66.54.48 Fax : (33)04.68.50.27.85
Sales department : Frank HERRY-CODERCH - Technical department : Olivier FORCADELL