Application; Theory Of Operation - ABB REC 561 User Manual

ABB Network Partner AB
Version 1.0-00
October 1996
Function:

1 Application

2 Theory of operation

Pulse counter
Optional
The Pulse Counter function provides the Substation Automation system
with the number of pulses, which have been accumulated in the REC 561
control terminal during a defined period of time, for calculation of, for
example, energy values. The pulses are captured on the Binary input mod-
ule (BIM) that is read by the Pulse Counter function. The number of
pulses in the counter is then reported via LON to the station MMI or read
via SPA as a service value.
The normal use for this function is the counting of energy pulses for kWh
and kvarh in both directions from external energy meters. Up to 12 binary
inputs in a REC 561 can be used for this purpose with a frequency of up to
40 Hz.
The registration of pulses is done for positive transitions (0−>1) on one of
the 16 binary input channels located on the Binary input module (BIM).
Pulse Counter values are read from the station MMI with predefined
cyclicity without reset, and an analogue event is created.
The integration time period can be set in the range from 30 seconds to 60
minutes and is synchronized with absolute system time. That means, a
cycle time of one minute will generate a Pulse Counter reading every full
minute. Interrogation of additional Pulse Counter values can be done with
a command (intermediate reading) for a single counter. All active
counters can also be read by the LON General Interrogation command
(GI).
The Pulse Counter in REC 561 supports unidirectional incremental
counters. That means only positive values are possible. The counter uses a
32 bit format, that is, the reported value is a 32-bit, signed integer with a
range 0...+2147483647. The counter is reset at initialization of the control
terminal or by turning the Pulse Counter operation parameter Off/On.
The reported value to station MMI over the LON bus contains Identity,
Value, Time, and Pulse Counter Quality. The Pulse Counter Quality con-
sists of:
• Invalid (board hardware error or configuration error)
• Wrapped around
• Blocked
• Adjusted
The transmission of the counter value by SPA can be done as a service
value, that is, the value frozen in the last integration cycle is read by the
station MMI from the database. The Pulse Counter function updates the
value in the database when an integration cycle is finished and activates
the NEW_VAL signal in the function block. This signal can be connected
to an Event function block, be time tagged, and transmitted to the station
MMI. This time corresponds to the time when the value was frozen by the
function.
1MRK 580 187-XEN
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