Interfacing with modern power analyzers

REQUIREMENTS FOR FIELDBUSES IN EDRIVE APPLICATIONS

Before selecting a fieldbus, it’s important to understand who the user is and what is the purpose the fieldbus should fulfill. First let’s talk about the user. There are two big user – groups. The OEMs, End customer. Their requirement is to connect the Power Analyzer to a Data Acquisition Software to record data fast for further analysis. In that respect the term “data” needs to be a little bit more explained. In terms of the Power Analyzer the term Data is used for Results which a calculated cycle-based and published onto the fieldbus. For HBK Power Analyzers this is up to 2000 Result Blocks per Second. For those who want to have the Raw Data transferred, we us the EtherNet over RJ45. To minimize the load of EtherNet the Raw Data could be stored on the SSD inside the Power Analyzer or on the SSD of the Computer over Ethernet RJ45.

The second big user- group are the System Integrators. They usually work only with the Results transferred over a fieldbus with the above-mentioned update rate. The Data must be available at a defined time frame (real time) with a very low latency (typ. 1ms). This is important in case of any control mechanism attached to the Automa- tion System. There are a few more requirements to mention. System-In- tegrators are looking for fieldbuses which

• have Low latency
• have High Data throughput
• are Cost effective
• are Time effective
• have less effort to implement
• are high reliability
• are well known on the market
• are potentially already available in the test bench
• give the possibility to remote control the Power Analyzer

FIELDBUSES AVAILABLE FOR HBK POWER ANALYZER

Some of those fieldbuses require additional hardware in the Power Analyzer like EtherCAT® or CAN|CANFD others are connected to RJ45 Ethernet.

GENERAL SETUP OF AVAILABLE INTERFACES

All Interfaces for the HBK Power Analyzer belong to the GenesisHighSpeed Mainframe. The settings we are talking about will be found in the Settings Sheet “Publishing” For each available fieldbus there is a column available that allows to select a signal. If necessary, there might be more columns available for more options like shown for EtherCAT® and CAN. If an interface does not pop up here, it might not be available for use. Even so, if an interface is available and visible, but not useable, than usually somethings need to be activated or a setup changed.

Before you start publishing, you need to setup you eDrive application. As this is not part of this document, I only will mention, that we are now working on a standard simple drive line with a Battery, a 3-phase Inverter and 2 Torque flanshes.

All fieldbuses can work in parallel and independent with the Automation System or an attached Software like CANape® from Vector. Figure 5 also shows a column which is called “Fieldbus name”. We know that some Automation Systems are having problems to interpretate the default fieldbus names created by the Perception software. Instead of wasting RT-FDB resources, it is possible to use this column to map the default names with a name accepted by the Automation System. This names are not used for storing or exporting Data but they will be used in the configuration files for CAN (CAN-DBC), EtherCAT® (ESI-file) or XCPoEtherNet (A2L-file). The GenDAQapi can retrieve the names directly. For all fieldbuses the latency is equal. The latency time is also published in this sheet as well as it is published on the fieldbus as information for the Automation System.

Let’s walk through step by step:

Mainframe: this is the name of the mainframe. This name can be changes in the hardware view of the Perception Software.

Resource usage: each formula, which is created in the RT-FDB uses Mainframe resources. At a point in time it might be to much calculations and the available resources are running out of space. The number of calculations is depending on the mainframe type. Most of the calcula- tions are done on each Recorder (e.g GN310B) to share the load. The number of shown in the Status bar is the one from the Recorder loaded the most.

CAN bus out load: this number indicates the additional load caused by the selected CAN signals to be published, the update rate and the bus speed. It’s not taken into account what real load is on the CAN bus.

RT-FDB latency: is an indicator for the latency which is caused by the calculation and directly effects the fieldbus

Fixed latency: some Automation Systems or operations need a delay to sync.

The following table show all fieldbuses with some more information

For more setup information please refer to one of the White papers explaining the dedicated fieldbus or contact our support team support-ept@hbkworld.com