GE Industrial Solutions Entellisys System User Manual - Manual (Page 121)

Waveform capture operation 121
9
9.4 Waveform capture operation
All waveform captures are performed on a system-wide basis. This means that for every
waveform capture, all available channels are recorded simultaneously. The following channels
are recorded from each EntelliGuard Messenger:
• Analog – Ia, Ib, Ic, In, Va, Vb, Vc (or Vba, Vbc, Vca for delta PT configurations)
• Digital Command Transitions – Open, Close, and Trip
• Digital Status Transitions – Open, Closed, Spring Charge, Analog IOC, Backup Trip
All channels for the entire system are time-synchronized to within 5us of each other. The
number of system-wide waveforms held in memory is dependent on the number of Messengers
in the system. The capacity can be calculated as the integer quotient of 1000/n, where n
represents the total number of Messengers in the system. Other specifications for waveforms
are:
• Sampling Rate – 64 samples / cycle
• Duration – 1 second (60-Hz systems); 1.2 second (50-Hz systems)
• File Format – COMTRADE (IEEE Std. C37-111-1999)
Because of the large memory capacity of the CPU, these parameters are fixed for all captures.