Functional Description; Analog Inputs - Measurement Computing PCI-DAS64/M1/16 User Manual

Functional Description

PCI-DAS64/M1/16 block diagram
The PCI-DAS64/M1/16 is a multifunction measurement and control board that provides the following features:
! 32 differential or 64 single-ended 16-bit analog inputs
! Two 16-bit analog outputs
! 32 digital I/O channels
!
One 16-bit counter
PCI-DAS64/M1/16 functions are illustrated in the block diagram shown here.
Gain and Offset Autocal
Mux
Analog In
&
64-CH single-ended
Gain
32-CH differential
TRIG_LO TRIG_HI
Analog
Trigger
A/D Start/Stop Trigger
A/D Pacer Gate
A/D External Pacer
SSH Out
A/D Internal Pacer Out
24-bits DIO
PortA
FIRSTPORTA (7:0)
PortB
FIRSTPORTB (7:0)
FIRSTPORTC (7:0) PortC
Inputs
DIN (3:0)
Outputs
DOUT (3:0)

Analog inputs

The PCI-DAS64/M1/16 provides 32 fully differential or 64 single-ended analog inputs. The input mode is
software selectable, with no switches or jumpers to set. The PCI-DAS64/M1/16 offers a 1 MHz sample rate.
The board offers full speed acquisition in single channel scans, and will perform full accuracy multi-channel
scans of up to 1.5 MHz, depending on the operating mode. An 8 K sample gain/channel queue is available
making long, complex sample sequencing simple. An 8 K sample FIFO buffer combines with Bus-Master DMA
and scatter-gather to assure data taken from the board is transferred into computer memory without missing
samples.
Queue ADC
Buffer Buffer
(8K) (8K)
Holding
REG
16-bit
ADC
EOC
1 MHz
STC
ADC
Memory
CNTL
CNTL
Trigger
CNTL
Queue
ADC
CNTL
Pacer
Sample
CNTL
Control /
Decoder
Status
40 MHz
Regs
16
DMA
PCI Bridge
Boot
w/BUS Master
DMA
EEPROM
PCI Bus (5V, 32-bit, 33 M z)
Figure 4-1. PCI-DAS64/M1/16 functional bock diagram
DAC 0/1
32K x 16
Buffer
SRAM
(16K)
Memory Bus
16
External D/A Trigger/Pacer Gate
DAC
CNTL
D/A External Pacer In
DAC DAC Pacer Out
Pacer
DAC RT
CNTL
DMA IRQ
Interrupt In
CTRL CTRL
Local Bus
C 0 H
CH1
H
4-1
Chapter 4
Gain and Offset Autocal
D/A OUT0
DAC0
16-bit, 100 k z H
D/A OUT1
DAC1
16-bit, 100 k z H
User
CNTR
0
CTR1 GATE
CTR1 CLK
CTR1 OUT