National Instruments DIO 6533 사용자 설명서
Chapter 3
Hardware Overview
© National Instruments Corporation
3-11
DIO 6533 User Manual
Table 3-1.
6533 Handshaking Protocols
Protocol
Peak Rates (MS/s)
at Various Cable
Lengths
REQ and ACK
Polarity
REQ Edge
That Requests
Transfer
Programmable
Delay Location
Delay Location
Complementary
Protocols
1 m
2 or 5 m
Asynchronous Protocols
8255
Emulation
Emulation
5
2.67
Active-low
Trailing
Between
transfers
transfers
Leading-Edge
Pulse
Pulse
Level
ACK
ACK
3.33
2.5
Programmable
Leading
Before ACK
and between
transfers
and between
transfers
Level ACK
Leading-
Edge Pulse
Edge Pulse
3.33
2.5
Programmable
Leading
Before ACK
and between
transfers
and between
transfers
Leading-Edge
Pulse
Pulse
Long Pulse
3.33
2.5
Programmable
Leading
For pulse width
and between
transfers
and between
transfers
Long Pulse,
8255
Emula-tion,
PC-DIO-24,
PC-DIO-96/PnP,
8255, 82C55
8255
Emula-tion,
PC-DIO-24,
PC-DIO-96/PnP,
8255, 82C55
Trailing-
Edge Pulse
Edge Pulse
1.8
1.5
Programmable
Trailing
For pulse width
and between
transfers
and between
transfers
Trailing-Edge
Pulse
Pulse
Synchronous Protocol
Burst
20
10*
Programmable
Neither
(level REQ)
(level REQ)
For clock speed
Burst
* Although asynchronous modes can adjust automatically to cable length, for synchronous modes, you must
select an appropriate speed for your cable at configuration time. Select a delay of at least the following: 0 for
a typical cable up to 1 m, 1 (100 ns) for a typical cable up to 5 m, and 2 (200 ns) for a typical cable up to 15 m
long.
select an appropriate speed for your cable at configuration time. Select a delay of at least the following: 0 for
a typical cable up to 1 m, 1 (100 ns) for a typical cable up to 5 m, and 2 (200 ns) for a typical cable up to 15 m
long.