National Instruments 321042A-01 Manual De Usuario
Hardware Configuration and Installation
Chapter 2
STD-GPIB for Windows
2-14
© National Instruments Corp.
Using Programmed I/O for GPIB Transfers
As an alternative to DMA transfers, you can use programmed I/O. To use programmed
I/O, you should disable DMA for the STD-GPIB by moving the jumpers as shown in
Figure 2 -9.
I/O, you should disable DMA for the STD-GPIB by moving the jumpers as shown in
Figure 2 -9.
DRQ 6
W3
DACK 6
DACK 5
DRQ 5
Figure 2-9. DMA Jumper Setting for No DMA Channel
Setting the Shield Ground Configuration
The STD-GPIB is set at the factory with the jumper in place to connect the logic ground
of the STD-GPIB to its shield ground. This configuration minimizes EMI emissions.
of the STD-GPIB to its shield ground. This configuration minimizes EMI emissions.
If your application requires that logic ground be disconnected from shield ground, follow
these steps:
these steps:
1.
Refer to Figure 2-3 to locate the shield ground jumper W4 on the STD-GPIB.
2.
Remove the jumper and place it across only one of the jumper pins, as shown in
Figure 2-10.
Figure 2-10.