Setting column
Alternatives
Description
Bit size
0
1)
Register bit size reduction not in
use. All bits in register used by
the value.
2...31
Register bit size reduced to this
value. Saturation limits of the
value according to the
configured bit size, including
possible sign bit.
Justification
Right
1)
After a value bit size reduction,
the remaining value bits are
aligned to the right (LSB) side of
the register.
Left
After a value bit size reduction,
the remaining value bits are
aligned to the left (MSB) side of
the register.
1) Default value
Multiplicative and divisor scaling are in principle similar operations, because any real
value can be used as scaling argument. For example, divisor scaling by 4 is the same
as multiplicative scaling by 0.25.
3.4.9
Event records
The IED creates a Modbus event record when a momentary digital input bit changes
its value. The IED then stores the changed Modbus bit location and value into the
Modbus event record buffer. The event time tag is also stored into the record. The time
tag includes a full time stamp from a year down to milliseconds.
Modbus event generation on/off is selectable for each individual momentary bit in the
Modbus memory map. It is possible to define whether events are to be generated from
the rising edge- or both edges' transitions of the momentary bit.
If the Modbus indication point is mapped to the user definable Modbus area, then the
possible events from this point come from the original Modbus point location. In case
the UDR mapped indication point has no original Modbus point location, then the
event comes from its UDR point location
Modbus events can also be generated from selected Modbus registers. This concerns
registers containing status information. In this case events would be generated each
time the register's integer value changes.
The size of the IED's internal Modbus event record buffer is 500 events. The 500 latest
events are at any time readable from the IED. When the Modbus event record buffer
becomes full, the IED overwrites the oldest event records in the buffer.
Multiple clients support
Several Modbus clients can independently of one another read out Modbus event
records from the IED. The Modbus event buffer keeps track of where in the event
Section 3
1MRS757645 B
Vendor-specific implementation
48
620 series
Communication Protocol Manual
