GE MI-869 Instruction Manual page 143

CHAPTER 4: SETPOINTS
Administrator Login and Commands via Modbus for 8 Series Relays
869 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
The slave response to this function code is the slave address, function code, a count of the
number of data bytes to follow, the data itself and the CRC. Each data item is sent as a two
byte number with the high order byte sent first.
For example, consider a request for slave 17 to respond with 3 registers starting at address
006B. For this example the register data in these addresses is as follows:
Address
006B
006C
006D
The master/slave packets have the following format:
Table 4-5: Master Packet Format for Function Code 03H
MASTER TRANSMISSION
SLAVE ADDRESS
FUNCTION CODE
DATA STARTING ADDRESS
NUMBER OF SETPOINTS
CRC (low, high)
Table 4-6: Slave Packet Format for Function Code 03H
SLAVE RESPONSE
SLAVE ADDRESS
FUNCTION CODE
BYTE COUNT
DATA 1
DATA 2
DATA 3
DATA 4
CRC (low, high)
ASE 2000 V2 Example
--> 00 00 00 00 00 06 FE 03 4A 8A 00 04
--> 00 00 00 00 00 0B FE 03 08 00 00 04 B0 00 00 00 64
Logging in as Administrator
Logging in as Administrator is demonstrated in the example below. The process requires
writing 44 bytes which consist of the Role ID and Password. Password characters are 22
bytes and role characters are also 22 bytes. The logging in must be done using a single
Modbus command using Function 10H (Store Multiple Setpoints).
The following table shows data to be written to the relay to login as Administrator. The
relay password in this example is 0.
Data
022B
0000
0064
BYTES EXAMPLE
1 FE
1 03
2 4A 8A
2 00 04
2 67 F4
BYTES EXAMPLE
1 FE
1 03
1 08
2 00 00
2 04 B0
2 00 00
2 00 64
2 E7 75
DESCRIPTION
message for slave 254
read registers
data starting at 4A8A
4 registers = 8 bytes total
CRC error code
DESCRIPTION
message from slave 254
read registers
4 registers = 8 bytes total
value in address 4A8A (16-bit)
value in address 4A8B (16-bit)
value in address 4A8C (32-bit)
CRC error code
DEVICE
4–25