envea STACK 710, Руководство пользователя

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4 Getting Started STACK 710
38
(PC-000878-MA Issue 7, December 2021)
ENVEA UK Ltd
4.13 Modbus Registers
A brief list of the most useful Registers is in section
. .2
. A complete list is
included on the CD-ROM.
Note: The definition of Register Numbers given in the Modbus standard can confuse. For
historical reasons, Registers are given decimal numbers beginning at 1, but
Register 1 is located at Address Offset 0. Register numbers are always one greater
than their associated bus addresses. The Table below uses Register Numbers.
4.13.1 Scaling
In the Table below, the value in the Modbus register must be divided by the scaling
factor to obtain the actual value.
4.13.2 Read-Only Registers
Modbus
Register
Data
Value
Description Range Scaling
127 Opacity Calculated opacity -25% - 100% x100
128 Optical
density Calculated optical
density -1 - 3 x1000
129 Dust
density Calculated dust
density 0 - 9999 x1
130 Dust
density
fractional
Fractional
part of the
dust density
(Reg 503)
0 - 99 x100
131
Average
optical
density
Average
optical
density
during
gravimetri
c test
-1 - 3 x1000
132 Stored
Average
Optical
Density
Stored average
optical density -1 - 3 x1000
133 Held
opacity
Calculated opacity
not updated during
a cal audit or a cal
check
-25% - 100% x100
134 Held optical
density
Calculated optical
density not
updated during a
cal audit or a cal
check
-1 - 3 x1000
135 Held dust
density Calculated dust
density not
updated during
a cal audit or a
cal check
0 - 9999 x1
136 Held dust
density
fractional
Fractional part of
the held dust
density (Reg 506)
0 - 99 x100
73 Alarm
status Transceiver alarm
0 = Inactive
1 = Active
NA