Accessing Event And Alarm Data - Emerson Micro Motion 3711 Configuration And Use Manual

Modbus Interface
5. Read and interpret the reply as follows:
• If EFM Modbus is disabled, the first two values in the data field are floating-point values
representing the timestamp and datestamp (in that order) for the history archive. The
datestamp uses the current year, with no modifications. For example, for calendar year
2005, the YY value is 05. Note that this is different from the YY value in event and alarm
log data.
• If EFM Modbus is enabled, the first two values in the data field are floating-point values
representing the datestamp and timestamp (in that order) for the history archive. The
datestamp uses the current year, with no modifications. For example, for calendar year
2005, the YY value is 05. Note that this is different from the YY value in event and alarm
log data.
• All subsequent values in data field: One floating-point value for each history point that
was specified in the History Access Registers panel. The values are retrieved sequentially,
beginning with the value specified for Starting History Point.
Table 12-7 Modbus history data requests
Modbus
function code Register bytes
03 7160
7161
7162
703
704
705
User-defined
(1) Default register. Register number may be changed in History Access Registers panel.
(2) Default register. Register number or contents may be changed in History Access Registers panel.
(3) Refer to History Access Registers panel for register number and contents.
12.6.3

Accessing event and alarm data

Event and alarm log records are returned together. When the Model 3711 receives a request for event
and alarm log data, it collects all "unacknowledged" records. Records are collected in the following
order:
• All event records, oldest first
• All alarm records, oldest first
146
Data field
Data bytes
(1)
N/A
(1)
N/A
(1)
N/A
(2)
Daily index current
value minus 1
(2)
Hourly index current
value minus 1
(2)
Extended history index
current value minus 1
(3)
User-defined
Description
Requests current index value for standard
history, daily recording. Possible responses are
1 to 35, representing the index of the next record
to be written.
Requests current index value for standard
history, hourly recording. Possible responses
are 1 to 840, representing the index of the next
record to be written.
Requests current index value for extended
history.
Requests most recent record from standard
history, daily database.
Requests most recent record from standard
history, hourly database.
Requests most recent record from extended
history database.
Requests most recent record from specified
history database. Record will contain
user-defined history points.
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Micro Motion Model 3711 Gas Flow Computers