TPU2000/2000R Modbus/Modbus Plus Automation Guide
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The TPU2000R may be configured to capture eight, four, two or one record(s) containing 8, 16, 32, or 64 cycles
of data. Several data elements are stored in each waveform record. Such information as the individual quantity
for each of the voltage/current phases, breaker 52a/b state, time-stamping information, and state of the protective
function is retrievable via Modbus and Modbus Plus.
OSCILLOGRAPHIC data contains two elements of particular interest to the Automation Specialist. One element
is the configuration of the oscillographic component as to when to acquire the data. The other element is retrieval
of the wave form functions and the understanding of how to interpret the data for display purposes.
Oscillographic Configuration (12 Registers Defined)
One can configure the TPU2000R to capture pre-fault and post fault snapshots of data. The trigger to capture the
data may be of the master trip element, breaker position, hard wired contact (Waveform Capture Initiate Element)
or if any of the 20 defined protective elements are energized. The control and status block is defined in 6X
Registers 63968 through 63199. The 6X file number for storage/retrieval of this data is in FILE 1 of the protocol.
Figure 5-60 illustrates the method to configure the oscillographics over Modbus or Modbus Plus. The host may
retrieve the data via the 6X memory read command by first writing a value of “2” to the first memory location of
the Oscillographic data block. The control register is defined as 63968. The registers from 63969 and 63970
should also be written with the appropriate unit password to effectuate the transfer of data from the TPU2000R to
the Modbus Memory Map. The configuration data will then be transferred from the TPU2000R to the 6X registers
reflecting the state of the Oscillographic configuration.
It should be remembered that some hosts are not capable of 6X register access. Parameterization of the
Oscillographic Data Capture may be accomplished from the WinECP (WINdows External Communication
Program) utility.
The definition of several key parameters must be understood in order to configure the waveform capture
(Oscillographic) capabilities of the relay. The relay must not be parameterized (or re-parameterized) while the
relay is monitoring the waveform for capture. Register 63972 controls the start/stop capabilities of this feature.
Register 63973 controls the storage capacity within the waveform capture buffer as shown in Figure 5-59. For
example, if a value of 0 is selected, Eight records of data can be captured and stored by the TPU2000R upon the
trigger action as defined in Registers 63975 through 63979. If the value of 3 is selected, a single record of data is
captured, filling the entire buffer. The data captured for each channel consists of 8 samples per quarter cycle per
channel (each of the eight channels are Ia, Ib, Ic, In, Va, Vb, and Vc).
Table 5-53 explains the resolution of the
capture. The 6X register Definition is included in Table 5-51.
Register 63974 configures the TPU2000R Trigger Mode. If Normal Mode (Value = 0) is selected, the trigger will
allow waveform capture until capture is terminated by the host. If the buffer is full, the waveform will roll over and
overwrite the first record in the buffer. If Single Shot (Value = 1) is selected, oscillographic capture monitoring will
be terminated upon recording of the single event record.
Append Mode is a mode in which each individual bit of the Trigger Register 63975 – 63979 is evaluated. If one of
the programmed trigger bits is active, the oscillographic data is stored. If during that time a second trigger bit is
active, a second record shall be recorded and stored. If the Normal/Append (Value =3) Mode function is selected,
the oscillographic function will continue at the end of waveform capture. If the buffer is full, then the next record
will overwrite that record at the beginning of the buffer. If the Single Shot/Append Mode is selected, then the
oscillographic function will terminate at the end of recording for that record.
Table 5-53. Oscillographic Resolution Capabilities
Register 63077 Selection
Description
0 = 8 Cycles per record –
8 Records
8 Records of Data Capture possible with 8 Cycles of Waveform
Captured @ 32 Samples per cycle per channel.
1 = 16 Cycles per record –
4 Records
4 Records of Data Capture possible with 16 Cycles of Waveform
Captured @ 32 Samples per cycle per channel.
2 = 32 Cycles per record –
2 Records
2 Records of Data Capture possible with 32 Cycles of Waveform
Captured @ 32 Samples per cycle per channel.
3 = 64 Cycles per record –
1 Record
1 Record of Data available possible with 64 Cycles of Waveform
Captured @ 32 Samples per cycle per channel.
