Справочник Пользователя для National Instruments NI-VXI
Chapter 6
NI-VXI Configuration Utility
6-10
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Caution
There is a potential problem when opening up a shared memory region to point
to system RAM. The PCI bus may return a retry on any cycle into system RAM. As a
consequence, an external VXI/VME device accessing the system RAM may get a
VXI/VME retry back. If the external VXI/VME device does not support VXI/VME retry,
the VXI/VME device will falsely detect the retry condition as a bus error condition.
consequence, an external VXI/VME device accessing the system RAM may get a
VXI/VME retry back. If the external VXI/VME device does not support VXI/VME retry,
the VXI/VME device will falsely detect the retry condition as a bus error condition.
VXI/VME devices that support retries will not have this problem, because they can handle
VXI/VME retry conditions correctly by automatically retrying the access. For example, the
National Instruments VXI-DAQ boards handle VXI/VME retry conditions properly and do
not exhibit this problem.
VXI/VME retry conditions correctly by automatically retrying the access. For example, the
National Instruments VXI-DAQ boards handle VXI/VME retry conditions properly and do
not exhibit this problem.
Resource Manager Delay
The only option under the Resource Manager portion of the Logical
Address Configuration Editor is the Resource Manager Delay control.
Address Configuration Editor is the Resource Manager Delay control.
Resource Manager Delay
Note
This field is effective only when the PCI-MXI-2 is at its default logical address of 0.
The PCI-MXI-2 is the Resource Manager only if its logical address is 0.
This field specifies the time in seconds that the Resource Manager (RM)
waits before accessing any other VXI/VMEbus device’s A16 configuration
registers.
waits before accessing any other VXI/VMEbus device’s A16 configuration
registers.
RM Delay Range
Default Value
0 to 65535 s
5