
TPU2000/2000R Modbus/Modbus Plus Automation Guide
75
dependent upon the TPU2000/2000R and the ratio of the PT and CT’s used. The CT and PT values are entered
into the TPU through ECP/WinECP in the Configuration Settings Menu illustrated in Figure 5-14
.
However, life as
we know it, is not perfect. Many SCADA hosts are unable to interpret the 32-bit value received over a network.
What can be done? ABB’s answer is to provide for a fill-in-the-blanks method of scaling. This method takes the
interpreted value and provides for DIVISOR SCALING (taking the MMI/network register values and dividing by a
constant) or a RATIO SCALING (taking the MMI values/network register values, PT Ratios, CT Ratios and Full
SCALE Metered Readings) and transform it into a raw scaled value depending on the minimum/maximum value
the SCADA system can interpret. The SCADA system must then receive the mathematical value and perform its
own internal calculations so that the data may be displayed to the operator which mirrors that displayed on the
relay’s front panel.
E
C
NORMAL
FAIL
P ICKUP
RECLOSE R OUT
SYS TE M RE S ET
TIME
INST ANTA NE OUS
FREQUENCY
NEG ATIVE S EQUE NCE
TARGE T RE SET
STATUS
TARGETS
A
B
C
N
DPU
2000R
Netwo rk
Partn er
V1.0
TPU2000R
32
Mappable
Registers
Change Register Configuration
400001
400002
400003
400004
400005
400032
User Definable Register 40005
Scale
500
Source Register Address (4XXX)
265
Destination Data Type
Bipolar (LSB)
Destination Data Size
12 Bit
Source Scale Type
Voltage
Source Data Type
Unsigned 32 Bit
To Accept Changes: Press Enter Return
No Change: Press Escape Key
High Word Van
Low Word Van
40265
40266
TYPICAL SCALING EXAMPLE
Figure 5-25. Register Scaling Methodology
Figure 5-26. Change Configuration Settings Menu Illustrating CT and VT Configuration
ABB Data Type Definitions
All definitions within this manual shall be based upon bits or registers. The ABB concept of Register Scaling and
Remapping is based upon the Modbus address map contained within this protocol document, it is essential to
understand Modbus Protocol even when providing Register Scaling and Remapping for DNP, Modbus Plus or
Standard Ten Byte Protocols.
For example, Modbus requires all register values to be reported in 16 bit portions (1 word). Two registers may be
combined to form numeric representations for IEEE notations, long signed (a number from –2,147,483,648 to
+2,147,483,647) or unsigned numbers( a number from 0 to +4,294,967,295). If a value is requested in the short
form ( a number from –128 to +127, or 0 to 255), 16 bits will be returned as a response to the host’s request, but
the number will be within the range of an 8 bit integer.
Summary of Contents for TPU2000
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