Operation Principle - ABB RELION REX640 Technical Manual

1MRS759142 C
3.20.14.4
REX640
Technical Manual
The pulses are captured by the binary input module and read by PCGAPC with a
frequency of up to 40 Hz. PCGAPC can also be used as a general-purpose counter.

Operation principle

The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "on" and "off".
The operation of PCGAPC can be described with a module diagram. All the modules
in the diagram are explained in the next sections.
PULSE_INPUT
RESET
FREEZE_COUNT
READ_VALUE
GUID-99BBAEE4-E876-4391-8D17-DDFE2F80E3A7 V1 EN
Figure 125: Functional module diagram
Pulse counter
This module counts the number of pulses available at PULSE_INPUT. The count
value is incremented depending upon Count criteria setting.
Table 230: Relation between setting Count criteria and count value behavior
Count criteria values
Rising edge
Falling edge
On change
Freeze
The count value is available at COUNT_VALUE in the Monitored data view and is
stored in a nonvolatile memory. This output is updated cyclically and sent to the
station HMI over various communication protocols, depending on the Reporting
interval setting. The start of Reporting interval corresponds to the start of the function
operation in the protection relay.
Binary output VALUE_READ activates for a fixed 200 ms each time the reporting
timer completes its cycle. It is also possible to update COUNT_VALUE before
completion of Reporting interval and make it available for communication by
providing a minimum 1-second-long pulse at READ_VALUE input. Besides
Pulse
Scaling
counter
PULSE_INPUT count value
Count value is incremented on the rising edge of
PULSE_INPUT
Count value is incremented on the falling edge of
PULSE_INPUT
Count value is incremented each time a rising
edge or falling edge is available at PULSE_INPUT.
Counting is frozen.
Section 3
Basic functions
VALUE_READ
COUNT_SAT
245