Reading Last Trip Target Messages - GE Multilin 850 Communications Manual

USING THE MEMORY MAP

Reading Last Trip Target Messages

Table 12-11: Modbus Map entries, Targets
Modbus Hex Description
Address Address
30273 0x0110 Target Count
30766 0x0111 Target Cause
12-12
1st 16 bits High Order Word of Long Value
unsigned 32 bits Unsigned Long Value
unsigned 32 bits Unsigned Long Value, 3 Decimal Places
For example:
Phase A Current value on relay display: 183.594 A
Phase current values read from Phase A Current Modbus registers:
04F5 (31270): 0002
04F6 (31271): CD2A
Combine the two 16 bit values into a 32 bit unsigned value: 183594
Apply the decimal point rule (divide by 1000): 183.594 A
Register: 31270
0002
183594
183.594
Target messages are read through the Modbus Target Message registers.
Min Max
0 256
0 0xFFFFFFFF
Follow these steps to obtain the Last Trip message:
1. Read address 30273 (0x0110) to obtain the Target Count.
2. Write the value obtained from Target Count register to select the Target Index register
at address, for example: 40230 (0x00E5). This will position the Target Message Index at
newest Target Message.
3. Read the Target Cause register for the newest Target Message to obtain the Target
Message cause.
For example, here are 3 Target Messages, with a Target Count of 3.
Target Index # 3
Target Index # 2
Target Index # 1
In this example, the following values are read from the Target Registers:
Target Index # 3 Value:
Target Index # 2 Value:
Target Index # 1 Value:
In order to interpret the target messages, we need to refer to the appropriate function
codes:
For Target Index #1: Link Error Primary
The value in Target Message Register 0111(hex) is 0x0000.
CHAPTER 12: ABOUT THE MODBUS MEMORY MAP
2nd 16 bits Low Order Word of Long Value
Register: 312701
CD2A
Step Units Format
Code
1 F0
1 FC134
GND IOC 1 OP
GND IOC 1 PKP
Link Error Primary
0x00CO, 0xF202
0x00CO, 0xF201
0x0000, 0x0037
8 SERIES PROTECTIVE RELAY PLATFORM – COMMUNICATIONS GUIDE
Factory Size in 8 8 8
Default Words 5 6 8
0 9 9
0 1 Y Y Y Y
0 2 Y Y Y Y
8
4
5