Analog output pacing and triggering, Digital input/output, Analog output pacing and triggering -8 – Measurement Computing PCI-DAS64/M2/16 User Manual
Page 29: Digital input/output -8
 
PCI-DAS64/M2/16 User's Guide
Specifications
Analog output pacing and triggering
Table 12. Analog output pacing and triggering specifications
Internal counter – ASIC 
External source (D/A external pacer) 
D/A pacing 
(software-programmable) 
Software paced 
External digital (external D/A trigger/pacer gate) 
D/A gate sources 
(software-programmable) 
External analog (analog trigger in) 
External digital: Programmable, active high or active low, level or edge 
D/A gating modes
External analog: Software-configurable for above or below reference. Gating levels are 
set by DAC0 or DAC1. 
External digital (external D/A trigger/pacer gate) 
D/A trigger sources
Software triggered
D/A triggering modes
External digital: Software-configurable for rising or falling edge. 
From 16 k RAM buffer via DMA (demand or non-demand mode) using scatter gather. 
Programmed I/O 
Data transfer
100 kS/s max per channel
Digital input/output
Table 13. Digital I/O specifications
Output: 74LS175
Digital type (main connector)
Input: 74LS244
Configuration
Four inputs, four outputs (DIN0 through DIN3; DOUT0 to DOUT3)
Output high voltage (IOH = -0.4 mA)
2.7 V min
Output low voltage (IOL = 8 mA)
0.5 V max
Input high voltage
2.0 V min, 7 volts absolute max
Input low voltage
0.8 V max, –0.5 volts absolute min
Digital type (digital I/O connector)
82C55
Number of I/O
24 (FIRSTPORTA Bit 0 through FIRSTPORTC Bit 7) 
2 banks of 8 and 2 banks of 4, or 
3 banks of 8 or 
Configuration
2 banks of 8 with handshake
Input high voltage
2.0 V min, 5.5 V absolute max
Input low voltage
0.8 V max, –0.5 V absolute min
Output high voltage (IOH = -2.5 mA)
3.0 V min
Output low voltage (IOL = 2.5 mA)
0.4 V max
Power-up / reset state
Input mode (high impedance)
SSH output
TTL compatible output, HOLD is asserted from start of the conversion for 
Channel 0 through conversion of the last channel in the scan. Available at user 
connector (SSH OUT / D/A PACER OUT). This pin is software selectable as 
SSH OUT (default) or D/A PACER OUT. 
SSH polarity
HOLD high (default) or HOLD low, software selectable
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