National Instruments DIO 6533 사용자 설명서

© National Instruments Corporation

5-1

DIO 6533 User Manual

This chapter provides detailed timing specifications for DIO 6533 
pattern generation and for the various full, two-way handshaking 
modes.

Pattern-generation timing is similar for digital data acquisition (input) 
and digital waveform generation (output). Data transfers are timed by 
request pulses, carried on the REQ pin. The 6533 devices can generate 
request pulses internally, or you can provide external pulses. Each 
request pulse strobes a data point into or out of the 6533 device. 

You can use up to two additional timing signals, if you select triggered 
pattern generation: a start trigger and a stop trigger. A start trigger, if 
used, begins the pattern-generation operation. A stop trigger ends the 
operation. However, you can specify a number of data points to transfer 
after the stop trigger. 

You can substitute a digital pattern for either the start or stop trigger. In 
this case, the operation begins or ends when the 6533 device detects a 
particular digital pattern on the data lines belonging to the group.

Figure 5-1 shows a pattern-generation operation using request pulses, a 
start trigger, and a stop trigger. 

Figure 5-1.  Pattern-Generation Timing

REQ

STOPTRIG

ACK (STARTTRIG)

Pretrigger Data

Posttrigger Data