ABB REM 610 Technical Reference Manual page 79

1MRS755537
Motor Protection Relay
Technical Reference Manual - ANSI Version
Special case 1: If there are no unread fault records, the contents of the last read
*
record is returned. If the buffer is empty, however, the registers contain only
zeros. This is the only time when sequence number zero appears.
Special case 2: If the master tries to read the next unread fault record without
*
entering selection code 1 again, the contents of the last read record will be
returned.
Selection code 2: the master reads the oldest stored record
By resetting the read pointer using selection code 2, the master can read the oldest
stored fault record. After this, the master can continue reading the following records
using selection code 1, irrespective of whether they have been read before.
Resetting the read pointer does not affect the sequence number of the
fault record.
A master reset, that is, clearing of targets and memorized values and
unlatching of output contacts, clears the fault records, after which the
sequence number starts from 1 again.
Event records
Modbus events are derived from SPA events. With a few exceptions, SPA events
update binary points in the DI and the packed HR area. Simultaneously, a
corresponding Modbus event record is generated. The event record contains the
Modbus DI/CO data point address and the value to which the point has changed (0
or 1). SPA events lacking a corresponding DI/CO data point are shown as SPA
channel and event code (informative event) in the event record. The maximum
capacity of the Modbus event buffer is 99 events. The time stamp of Modbus events
is extended to contain complete information, from date to millisecond.
To read an event record:
1. Write a preset single register command (function 06) to HR671 using a selection
code as data value.
2. Read the selected fault record (function 04) from HR672, register count 8.
Alternatively, a fault record can be read using one command (function 23) only.
Selection code 1: reading the oldest unread record
Status register 3 (HR403) informs whether there are unread event records (see
Fig. 5.1.14.1.-2). If there is one or several unread event records, the master can read
the contents using selection code 1.
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