Output Words Control Modes
Original instructions
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Purpose
This section describes output words 5 ... 16 control modes.
Output Words 5 ... 16
Output words 5 ... 16 are used as data for specific control modes.
NOTE: Be sure you read General Modbus Message Rules.
Output Words Mode Memory Allocation
Output word modes are used for message data. The table below describes the specific memory allocation for each control mode.
Control Mode 0
Control Mode 0 - Idle, Clear Response Buffer
Word 1
Sequence #
Word 2
Output Configuration
Output
Word 3
Control Mode 0
Word 4
Port Configuration
Slave node address
Words 5 ... 16
Not used
Control Mode 1
Control Mode 1 - Modbus Message
Word 1
Sequence #
Word 2
Output Configuration
Output
Word 3
Control Mode 1
Word 4
Port Configuration
Message length
Words 5 ... 16
12 words of message output data
Control Mode 2
Control Mode 2 - Block Write
Word 1
Sequence #
Word 2
Output Configuration
Output
Word 3
Control Mode 2
Word 4
Port Configuration
Slave node address
Word 5
Start address - value of 0 = 400001
Word 6
Number of data words, 1 ... 10 are valid
Words 7 ... 16
10 words of message output data
Control Mode 3
Control Mode 3 - 1 Block Write And 1 Block Read Command
Word 1
Sequence #
Word 2
Output Configuration
Output
Word 3
Control Mode 3
Word 4
Port Configuration
Slave node address
Word 5
First write command address - value of 0 = 400001
Word 6
Number of data words, 1 ... 8 are valid
Words 7 ... 14
8 words of message output data
Word 15
First read command address
Word 16
Number of data words to read, 1 ... 12 are valid
Control Mode 4
Control Mode 4 - 4 Single Write Commands
Word 1
Sequence #
Word 2
Output Configuration
Output
Word 3
Control Mode 4
Word 4
Port Configuration
Slave node address
Word 5
First single write command address - value of 0 = 400001
Word 6
1 word of message output data
Word 7
Second single write command address - value of 0 = 400001
Word 8
1 word of message output data
Word 9
Third single write command address - value of 0 = 400001
Word 10
1 word of message output data
Word 11
Fourth single write command address - value of 0 = 400001
Word 12
1 word of message output data
Words 13 ... 16
Not used
Control Mode 5
Control Mode 5 - 3 Single Writes and 1 Block Read Command
Word 1
Sequence #
Word 2
Output Configuration
Output
Word 3
Control Mode 5
Word 4
Port Configuration
Slave node address
Word 5
First single write command address - value of 0 = 400001
Word 6
1 word of message output data
Word 7
Second single write command address - value of 0 = 400001
Word 8
1 word of message output data
Word 9
Third single write command address - value of 0 = 400001
Word 10
1 word of message output data
Words 11 ... 14
Not used
Word 15
First block read command address
Word 16
Number of data words to read, 1 ... 12 are valid
Control Mode 6
Control Mode 6 - 2 Single Writes And 2 Block Read Commands
Word 1
Sequence #
Word 2
Output Configuration
Output
Word 3
Control Mode 6
Word 4
Port Configuration
Slave node address
Word 5
First single write command address - value of 0 = 400001
Word 6
1 word of message output data
Word 7
Second single write command address - value of 0 = 400001
Word 8
1 word of message output data
Words 9 ... 12
Not used
Word 13
Second block read command address
Word 14
Number of data words to read
Word 15
First block read command address
Word 16
Number of data words to read
NOTE: With control mode 6, words 14 and 16 combined length must be 1 ... 12.
Control Mode 7
Control Mode 7 - 1 Write And 3 Block Read Commands
Word 1
Sequence #
Word 2
Output Configuration
Output
Word 3
Control Mode 7
Word 4
Port Configuration
Slave node address
Word 5
First single write command address - value of 0 = 400001
Word 6
1 word of message output data
Words 7 ... 10
Not used
Word 11
Third block read command address
Word 12
Number of data words to read
Word 13
Second block read command address
Word 14
Number of data words to read
Word 15
First block read command address
Word 16
Number of data words to read
NOTE: With control mode 7, words 14 and 16 combined length must be 1 ... 12.
Control Mode 8
Control Mode 8 - 4 Block Read Commands
Word 1
Sequence #
Word 2
Output Configuration
Output
Word 3
Control Mode 8- 4 block read commands
Word 4
Port Configuration
Slave node address
Words 5 ... 8
Not used
Word 9
Fourth block read command address
Word 10
Number of data words to read
Word 11
Third block read command address
Word 12
Number of data words to read
Word 13
Second block read command address
Word 14
Number of data words to read
Word 15
First block read command address
Word 16
Number of data words to read
NOTE: With control mode 8, words 10, 14 and 16 combined length must be 1 ... 12.