Arb:Data Transfer:Advanced:Maximum In-Flight Read Requests Property

Arb:Data Transfer:Advanced:Maximum In-Flight Read Requests Property

Short Name: Maximum In-Flight Read Requests

Property of niRFSG

Specifies the maximum number of concurrent PCI Express read requests the RF signal generator can issue.

Supported Devices: PXI-5670/5671, PXIe-5672/5673/5673E

When transferring data from computer memory to device onboard memory across the PCI Express bus, the RF signal generator can issue multiple memory reads at the same time. In general, the larger the number of read requests, the more efficiently the device uses the bus because the multiple read requests keep the data flowing, even in a PCI Express topology that has high latency due to PCI Express switches in the data path. Most NI devices can issue a large number of read requests (typically 8 or 16). By default, this property is set to the highest value the RF signal generator supports.

If other devices in your system cannot tolerate long data latencies, it may be helpful to decrease the number of in-flight read requests the RF signal generator issues. This change helps to reduce the amount of data the signal generator reads at one time.

Related Topics

Improving Streaming Performance

Remarks

The following table lists the characteristics of this property.

Datatype
Permissions	Read/Write
High-level VIs	N/A
Channel-based	No
Resettable	Yes