FIELDBUS MONITOR SIMPLIFIES COMMISSIONING OF FIELDBUS SEGMENTS

2006 03 28

MTL-Relcom has announced the latest addition to its Foundation fieldbus™ H1 toolkit, the FBT-6 Fieldbus Diagnostics Monitor. The handheld device monitors a live fieldbus network without interfering with its operation, enabled via an impressive variety of features including noise measurements in 3 bands, monitoring of signal level for all devices, monitoring of signal to shield faults, network retransmissions and the ability to download data to a PC via a USB port. Aimed at maintenance personnel and Distributed Control Systems (DCS) suppliers, the FBT-6 is intended for easier and faster troubleshooting and commissioning of fieldbus segments by eliminating the need to manually record the values when connect ing a tester on each segment or device.

The device builds on the Relcom FBT-3 fieldbus tester - established as the standard for fieldbus H1 test equipment - and has been developed in collaboration with key end users, fieldbus training centres and systems companies. Feedback from these groups highlighted the complexity of collecting and recording the bus parameters required by modern fieldbus commissioning procedures. The new FBT-6 performs measurement and collection of all the key parameters, providing the user with a comprehensive baseline of the fieldbus physical layer.

The FBT-6 diagnostic monitor measures noise levels in fieldbus frequency, as well as low and high frequencies (3 bands) to help identify the source of noise on segment which may lead to communication errors. The device records peak and average noise levels based on this information. Monitoring of signal levels for all devices, as well as monitoring of signal to shield faults often caused by poor installation practice are important new measurement functions offered by the FBT-6 . These measurements clearly identify wiring errors which can be corrected during the commissioning procedure for the fieldbus system.

Network retransmissions are checked by the FBT-6 from each device on the segment. If a device fails to respond to 3 consecutive pass tokens, it will be removed from the control systems live communication list, while an alarm will alert the operator to the problem. Detecting retransmissions via the FBT-6 provides a key performance indicator of the health of the network, allow ing corrective action to be taken before a device is removed from the live list.

Data collected by the FBT-6 can be quickly downloaded to a PC via a USB port (FBT-6 Assistant software provided supports Windows XP and Windows 2000 ). The transferred files will be saved as comma separated files (.csv) and can be opened in Microsoft Excel, displaying the parameters and actual values of collected data in an easily readable format.

Hazardous area certification is now in progress which will allow the FBT-6 to be connected to intrinsically safe and non-incendive fieldbus systems without the need for a gas free permit.

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