The relationship between Emerson ROC field devices and CygNet history data groups is defined by the use of RAM areas, segments, points, and ordinals. To some extent, this is also true of FMS data groups because they depend on native history data groups for their data.
Because the process of configuring a CygNet data group to "talk" to a field device begins at the field device, the following information first provides details about field device history points, then native history data groups, and finally EFM data groups.
For more information, see the following subsections below:
In order for your Emerson ROC EIE to collect historical information for a given field device, that device must be properly configured. See the appropriate manufacturer-provided documentation.
Emerson ROC devices rely on a combination of RAM areas and points within RAM areas to identify history point numbers. Emerson ROC points contain standard and extended history parameters, as well as index information where applicable.
The following list breaks down RAM areas, segments, and points by model:
Note: The following section relates to the native history data groups "Periodic History," "Extended History," and "History — Sixty Minute Point."
Each CygNet data group added to a remote device is identified by a number called an ordinal. The ordinal is specified on the Data Group Properties dialog box. For native history data groups, the ordinal derives from an associated history point on a field device. Sometimes this is a one-to-one relationship, as with the FloBoss 107 device.
Note: Field device units must match the supported units of the history points they map to.
Emerson ROC devices rely on a combination of RAM areas and points within those RAM areas to identify history point numbers. Emerson ROC points contain standard and extended history parameters, as well as index information where applicable.
The following list breaks down RAM areas, segments, and points by model:
For an Emerson ROC EIE, poll the "History Point List" data group. History points appear in the Hist Pt# column. Segments do not apply to Emerson ROC devices; a RAM area is used instead.
FMS history data groups also use ordinals. However, these ordinals are associated with a meter, not a history point. When you specify a Meter# in an FMS history Data Group Properties dialog box, that number displays in the Ordinal column under the Data Group page.
Note: Field device history point units must match the supported FMS history data group units.
For all Emerson ROC models, the "FMS History" data groups must be manually configured with History Point numbers. The following procedure explains how to add point numbers to an Emerson ROC remote device that uses FMS.
Note: Poll the "ROC Config" data group before starting this procedure.