Ge 489 User Manual download pdf (Page 212)

6-50 489 Generator Management Relay GE Multilin

6.5 DNP POINT LISTS 6 COMMUNICATIONS

TABLE NOTES:

1. Unless otherwise specified, an event object will be generated for a point if the current value of the point changes by an

amount greater than or equal to two percent of its previous value.

2. An event object is created for the Frequency point if the frequency changes by 0.04 Hz or more from its previous value.

3. An event object is created for these points if the current value of a point is in any way changed from its previous value.

4. To support existing SCADA hardware that is not capable of 32-bit data reads, the upper and lower 16-bit portions of

these 32-bit values have been assigned to separate points. To read this data, it is necessary to read both the upper

and lower 16-bit portions, concatenate these two values to form a 32-bit value and interpret the result in the format

associated with the point as specified in Table 6–2: Data Formats on page 6–34.

5. The data returned by a read of the User Map Value points is determined by the values programmed into the corre-

sponding User Map Address registers (which are only accessible via Modbus). Refer to Section 6.3.2: User-Definable

Memory Map Area on page 6–8 for more information. Changes in User Map Value points never generate event

objects. Note that it is possible to refer to a 32-bit quantity in a user map register, which may require the use of a 32-bit

variation to read the associated analog input point.

6. The scale for pre-trip currents is determined by the value in point 9, which should not normally change

7. The scale for currents is determined by the value in point 47, which should not normally change

8. Each power quantity is available at two different points, with two different scale factors (kW and MW, for example). The

user should select the unit which is closest to providing the resolution and range desired. If 32-bit analog input capabil-

ity is present, the higher-resolution (kW, kvar, kVA) points should generally be used, since they provide the greatest

resolution.

9. Analog input values may be –50000 to +50000 if so configured. Therefore, 32-bit analog input capability is required to

read the full possible range. If the SCADA equipment can only read 16-bit registers, the analog inputs should be con-

figured to operate within the range –32768 to +32767.

10. Each neutral voltage quantity is available at two different points, with two different scale factors (volts and tenths of a

volt). The user should select the unit which is closest to providing the resolution and range desired. If 32-bit analog

input capability is present, the higher-resolution (tenths of a volt) points should generally be used, since they provide

the greatest resolution.

250 F13 Positive kvarh Class 2

251 F13 Negative kvarh Class 2

252 F12 Generator Hours Online Class 2

Table 6–8: ANALOG INPUTS POINT LIST (SHEET 4 OF 4)

INDEX FORMAT DESCRIPTION EVENT CLASS

ASSIGNED TO

NOTES

1 2 ... 207 208 209 210 211 212 213 214 215 216 217 ... 258 259

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Ge 489 User Manual Page 212