ABB Relion 620 Series Protocol Manual page 52

Section 3
Vendor-specific implementation
46
Table 25: Configuration columns in Modbus Communication Management tool in PCM600
Setting column
Initial properties
Scale value format
UDR register size (v2)
UDR register type
Rescaling
Table continues on next page
Alternatives
Regular Modbus register
1)
value
DA value from system level
1)
Same as the source register
16-bit
32-bit
1)
Same as the source register
Unsigned
Signed
1MRS757645 B
Description
UDR value initially inherits
scaling from the source Modbus
register. This includes the
Primary scale in
source value
use setting. If checked, the value
is automatically presented as a
primary value, according to the
system CT and VT ratio settings.
UDR value is initially the same
as the IEC 61850 value received
from system level. For current
and voltage measurements this
means PU value (1.0
corresponds to 1.0 × nominal
value).
If the Modbus source register is a
16-bit register, then the UDR
register is automatically also 16-
bit. This principle applies to 32-
bit registers, too.
UDR register is forced to 16-bit,
regardless of the source register
size.
UDR register is forced to 32-bit,
regardless of the source register
size.
If the Modbus register is an
unsigned register, also the UDR
register is unsigned. This
principle applies to signed
source registers, too.
The value is interpreted as a
positive value only.
The value is interpreted as a
signed two's complement value.
620 series
Communication Protocol Manual