TecMar --  AD212   Analogue to Digital Converter Board

The AD212 provided 16 single-ended or 8 true differential analogue to digital conversion inputs with 12 bit accuracy and a 30 KHz conversion rate.  The board came as a two board set with one board (itself with various options), piggy-backed on top of the other.

The board could be I/O or memory mapped -- switch selectable.  It could be jumper for selectable input ranges of:  +10V, ±5V, 0 to +10V, 0 to +5V.  Output formats were  two's complement, binary, offset binary.  Transfers data was in in 8 or 16 bit words with provision for expansion to 256 channels with other boards. There also was the capability of external trigger of A/D under computer control as well as auto channel  incrementing from any channel  to any channel.  It utilizes the S-100 vectored interrupt system.  Data was latched providing pipelining for higher throughput and data overrun detection.  The board had a high-speed sample-and-hold and precision multiplexer.

The Tecmar AD212 Software Support Package  (AD212-SSP)  was designed to help the user perform complex data acquisition tasks and timing operations with any S-100 computer operating under CP/M and using the Tecmar AD212.    The following tasks can be performed with the AD212-SSP:

1.        Set time of day

2.        Set 24 hour time of day

3.        Read time of day

4.        Read 24 hour alarm status

5.        Collect a given number of data points using the AD212 at a timer interval  varying from 40 microseconds to 64K seconds

6.        Optional  continuous visual  monitoring of the data being collected

7.        With the TM-DA100 an array of data  in memory was converted to an analog signal  that can be used to drive a plotter, oscilloscope, etc.

8.        An event counter was provided which can count from 0 to 64K

9.        A routine was provided which displays  the contents of an integer array on a video monitor .

The main component of the data acquisition sub-system is the large module on the daughter board which contains the 16 channel multiplexer,  sample-and-hold, analog to digital converter and related control  circuitry.    The AD212 is currently designed to accept at least nine different modules from two manufacturers.    These are  the  DT5701,   DT5702,   DT5703,   DT5710,  DT5712,  DT5714,  and DT5716 from Data Translation,  Inc. and  the MP6812 and MP6912A from Analoqic Corp.      These modules are not entirely plug compatible with one another so that a  number of jumpers are required on the daughter board to compensate for the incompatibilities.    There are also a number of optional modes of operation the selection of which requires additional  jumper areas.    The specific function of these jumpers are described when the related part of the circuit in the manual.
 
The manual for this unique board can be obtained here.
Tecmar provided a Fortran library of sub-routines to use with this board. This manual can be obtained here.

Other TecMar  S-100 Boards

Digital to Analogue Converter     Analogue to Digital Converter