ADLINK PXES-2780 18 Slot PXIe Chassis Deployment Configuration

Configurable PCIe Link Architecture

The PXES-2780 backplane PCIe switching architecture supports two link modes, which users can switch through monitoring software:

4-link x4 mode (factory default):

There are 4 x4 links from the system slot to the switch chip, with a total bandwidth of 8 GB/s;

All peripheral slots share the system bandwidth evenly, with each x4 peripheral slot having a bandwidth of 1 GB/s (Gen2 signal). This mode is suitable for multi module load balancing scenarios.

2-link x8 mode:

There are 2 x8 links from the system slot to the switch chip, with a total bandwidth of 8 GB/s;

Some dedicated peripheral slots (Slot 8, 9, 11, 12) can obtain x8 links, with a single slot bandwidth increased to 2 GB/s (Gen2). This mode is suitable for applications where high-throughput modules (such as high-speed digitizers and vector transceivers) require exclusive bandwidth.

Switching steps: Select the desired configuration (four-link x4 or two-link x8) in the "PXle Link" area of the Chassis Remote Mon. Utility, and click "Config" to apply. The new settings need to be restarted before they can take effect. This configuration capability enables PXES-2780 to flexibly adapt to testing tasks with different bandwidth requirements without the need to replace the hardware backplane.

Trigger bus and star trigger

4.1 Three stage trigger bus and bridge

The 18 slots of PXES-2780 are divided into three trigger bus segments:

Segment A: Plot 1-6

Segment B: Plot 7-12

Segment C: Slot 13-18

Each segment contains 8 trigger lines (TRIG<0-7>), and all slots within the segment share the trigger signal. The connection or isolation between segments is achieved through two trigger bus buffers. Users can independently configure the bridging status for each trigger line through monitoring software, achieving 8 different combinations of inter segment connections. This feature allows the chassis to be divided into multiple independent trigger domains, or all slots to be unified in the same trigger domain, greatly enhancing the flexibility of multi module synchronization.

4.2 Star Trigger (System Timing Slot 10)

Slot 10 serves as a system timing slot, providing 1 single ended star trigger (PXI_STAR) and 3 pairs of differential star triggers (PXIe-DSTAR) to each peripheral slot. The routing allocation is shown in Table 1-4 of the manual. For example, the PX_STAR line for Slot 2 corresponds to number 7, Slot 3 corresponds to number 6, and so on. Differential star triggering is allocated based on pairing. When installing a dedicated star trigger controller module, precise star trigger allocation can be achieved, which is particularly suitable for high-speed acquisition applications that require triggering multiple modules simultaneously. If this feature is not required, Slot 10 can also be used as a regular PXIe x4 peripheral slot.

Dual mode remote monitoring system

PXES-2780 provides two interfaces for communicating with the chassis management unit: SMBus (via system slot, ADLINK embedded controller required) and RS-232 serial port (rear DB-9, remote PC available). There is a significant difference in the functional support between the two interfaces:

Function SMBus RS-232 serial port

Chassis status monitoring (voltage/temperature/fan) support

Alarm threshold setting support

Triggering bus routing settings is not supported

PCIe link mode switching is not supported

Therefore, if only monitoring the status is needed, the RS-232 serial port can meet the requirements; If you need to configure the trigger bus or switch link modes, you must use the ADLINK embedded controller to access through SMBus.

5.1 Installation and use of monitoring software

The monitoring tool is located on the All in One CD (path: X: Driver Installation PXI Platform PXI chassis PXES-2780 xxxx Setup. exe) and is only compatible with ADLINK PXIe controllers. The third-party controller needs to be developed independently (refer to the function library documentation) or remotely monitored through RS-232.

After starting the software, the interface is divided into three parts:

Connect Control: Select the interface (SMBus or RS-232), click Connect/Start to establish communication, Stop/Disconnect to terminate; Log Chassis Status can record logs (supports overwrite/append, can set sampling period); Save/Load Threshold saves or restores threshold configuration.

Chassis Control&Alarm Threshold: The core control area includes triggering bus routing settings, PCIe link mode switching, target temperature setting, fan mode switching, and setting various voltage/temperature/fan alarm thresholds.

Chassis Status: Real time display of voltage readings, 8 temperature sensors (T1~T8, located on the back panel from left to right), 3 fan speeds, clear identification of normal/abnormal status.

5.2 Intelligent Fan and Target Temperature Setting

Rear fan switch (HIGH/AUTO):

HIGH: The fan maintains a constant full speed, suitable for high load environments;

AUTO: Dynamic speed regulation based on the highest temperature of the backplate.

Default fan curve: When the temperature is below 25 ° C, the fan operates at a 40% duty cycle; Linear increase after temperature exceeds 25 ° C; Full speed (100%) when reaching the target temperature (default 50 ° C). Users can modify the target temperature value (range 25 ° C~70 ° C) in the software, and click Set to take effect immediately. If a large number of high-power modules are installed inside the chassis, the target temperature can be lowered to 45 ° C, allowing the fan to enter full speed ahead of schedule and increasing the heat dissipation margin.