Moore Industries NET Concentrator System AOM, Руководство пользователя

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NET Concentrator System
®
NCS
- 102 -
Moore Industries-International, Inc.
www.miinet.com
Output Configuration : Current
Output Range: 4 to 20 mA
User Defined Integer Scaling: Disabled
The user wishes to set the output current to 12.34 mA. The following calculation is performed to determine what
value to write to the scaled integer register:
Scaled Int PV= (FloatPV-Float Zero) +4096
( ) 57344
FloatFull-FloatZero
Scaled Int PV= 33987 (0x84C3)
Scaled Int PV= (12.34-4.0) +4096
( )
57344
20.0 - 4.0
To obtain an output of 12.34 mA, a value of 33987 (0x84C3) should be written to the Channel’s Scaled Integer
register.
Example #2:
This example illustrates converting the Floating Point value to an integer value with a single fixed decimal point.
This makes it easy to look at the Scaled Integer, and interpret it with no fancy calculations (i.e. just shift the
decimal point to the left one position.) It also shows the resulting Scaled Integers if default behavior is used.
The input signal to a NCS TIM channel is a resistance with typical PV (Process Variable) values from 250 Ohms to
750 Ohms. It is desirable to also report the values below the expected 250 Ohms and above 750 Ohms.
Input Configuration: Ohms
Input Range: 250 to 750 ohms
User Defined Integer Scaling: Enabled
Integer Scaling Zero and Full: 2500 and 7500
Integer Scaling Zero and Full Limits: 1000 and 9000.
PV
149.0
150.0
250.0
500.0
750.0
850.0
851.0 0 (0x0000)
0 (0x0000)
4096 (0x1000)
32768 (0x8000)
61440 (0xF000)
65535 (0xFFFF)
65535 (0xFFFF) 1000
1500
2500
5000
7500
8500
9000 Out of Range
Out of Range
In Range
In Range
In Range
Out of Range
Out of Range
Default Integer
Scaling User Scaling
Enabled
Comment
For comparison, the table below shows the resulting integers using “Default Integer Scaling” and “User Defined
Integer Scaling”.
MODBUS Support Table 4.
Comparison of Integer Values by Method
Example #1-B: