GE Multilin 565 Instruction Manual page 106

FEATURE INFORMATION
Message Format and Example (numbers are expressed in
HEX)
Request slave 11 to respond with 3 setpoints starting at
address 006B. For this example the setpoints data in these
addresses is:
Address Data
006B 022B
006C 0000
006D 0064
Master Transmission:
HI LO
11 03 00 6B
ADDRESS FUNCTION START SETPOINT
CODE ADDRESS COUNT
Slave Response:
11 03 06
ADDRESS FUNCTION BYTE
CODE COUNT
FUNCTION CODE 04
Modbus Implementation: Read Input Registers
565 Feeder Management Relay Implementation: Read Ac-
tual Values
This function code allows the master to read a group of
actual values from a slave device. The maximum number of
input registers that can be read in one transmission is 125.
Number of input registers should match the total length of
required actual values. In other words, reading half of an
actual value is not recommended. For the 565 Feeder Man-
agement Relay implementation of Modbus, "input registers"
are equivalent to 565 Feeder Management Relay actual
values. Input registers are 16 bit (two byte) values transmit-
ted high order byte first. But all 565 Feeder Management
Relay actual values are not made of two bytes. Some of them
are four bytes long and in that case two consecutive input
register addresses are used to transmit data of one actual
value. Input register with lower address number carries two
more significant bytes.
The slave response to this function code is the slave ad-
dress, function code, a count of the number of data bytes to
follow, the data itself, and the CRC. Each data item (actual
value) is sent as a two byte number with the high order byte
sent first.
Note: Broadcast mode is not allowed with this function code.
The master transmission will be ignored by all slaves if
broadcast mode is used with this function code.
Message Format and Example
Request slave 11 to respond with 1 actual value starting at
address 0008. For this example the actual value in this
address (0008) is 0000.
Master Transmission:
6-8
HI LO HI LO
00 03 ?? ??
CRC
HI LO HI LO HI LO HI LO
02 2B 00 00 00 64 ?? ??
DATA DATA DATA CRC
HI LO
11 04 00 08
ADDRESS FUNCTION START
CODE ADDRESS COUNT
Slave Response:
11 04 02
ADDRESS FUNCTION BYTE
CODE COUNT
FUNCTION CODE 05
Modbus Implementation: Force Single Coil
565 Feeder Management Relay Implementation: Execute
Operation
This function code allows the master to request the 565
Feeder Management Relay to perform specific operations.
The operations that can be performed by the 565 Feeder
Management Relay are as follows:
Operation Code Function
00 Reset (keypad)
01 End of Relay Test
02 End of LED Test
03 End of Analog Output Test
04 Test LCD Display
05 Test LEDs
0FH Clear Maintenance Data
10H Clear Operations Data
11H Clear Amp Demand Data
12H Clear KW Demand Data
13H Clear KVAR Demand Data
14H Clear Events
Note: Broadcast mode is allowed with this function code.
When a broadcast transmission is sent by the master (ie.
SLAVE ADDRESS = 0) the selected operation will be ex-
ecuted by all slave devices on the communication link. No
response will be sent from any of the slaves.
Message Format and Example
Request slave 11 to execute operation code 1.
Master Transmission:
HI LO
11 05 00 01
ADDRESS FUNCTION OPERATION CODE
CODE CODE
(Perform Function)
Slave Response:
HI LO
11 05 00 01
ADDRESS FUNCTION OPERATION CODE
CODE CODE
FUNCTION CODE 06
Modbus Implementation: Preset Single Register
565 Feeder Management Relay Implementation: Store Sin-
HI LO HI LO
00 01 ?? ??
ACT. VAL. CRC
HI LO HI LO
00 00 ?? ??
DATA CRC
HI LO HI LO
FF 00 ?? ??
CRC
VALUE
HI LO HI LO
FF 00 ?? ??
CRC
VALUE