Allen-Bradley 5069-SERIAL, Руководство пользователя, Страница: 58 / 110

58 Rockwell Automation Publication 5069-UM003A-EN-P - May 2018
Chapter 4 Configure Compact 5000 I/O Serial Module
Table 13 - Master Command List Modbus Master Parameters
Parameter Definition
Communication Method Communication Method:
• Disabled
• Continuous - sending the command based on the Poll interval value.
• Conditional - only for Write command and triggered when the write value has changed.
– After initialization, the base value for conditional is 0. So if the first consumed data is not 0, the conditional command is transmitted.
If you want to use value 0, you must set another value and reset the value to 0 again.
Data Type • BOOL
• INT
• REAL
Function Code • Read Coil Status- This code reads Modbus addresses 000000…065535. These bit values indicate coil status.
• Read Input Status- This code reads Modbus addresses 100000…165535. These read-only bit values indicate discrete input status.
• Read Holding Registers - This code reads Modbus addresses 400000…465535. This is a 16-bit word value.
• Read Input Registers - This code reads Modbus addresses 300000…365535. They are also 16-bit word values, but are Read Only data.
The Modbus Master cannot write to these registers.
• Force Single Coil - This code writes to Modbus addresses 000000…065535. This command writes to only one coil.
• Preset Single Register - This code writes to Modbus addresses 400000…465535. This command writes to only one coil.
• Force Multiple Coils - This code writes to multiple coil values to the slave addresses 000000…065535.
• Preset Multiple Registers - This code writes to multiple register values to the slave device at addresses 400000…465535
For more information about Master Command List Function Codes see Appendix B .
Slave Address Node Address of the Modbus Slave device (1…247 and 0 for broadcast).
Modbus Address Offset (0-based) Offset to the actual Modbus Address. Holding Register address of 400003 is equal to 00003 in the Modbus Address offset. (0…65535).
Data Length Number of data points being read (1…125 for registers, 1…2000 for coils and discrete inputs) or written (1…123 for registers, 1…1968
for coils.
Poll Interval • 0 – keeps repeating as fast as possible.
• 1…32,767– the time, in seconds, for the command to be sent periodically in Continuous mode.
Swap Mode • No Change – no swapping of data
• Word Swap – Words are swapped before sending out, e.g., 11112222 = 22221111
• Byte Swap – each byte is swapped. e.g., 11223344 = 22114433
• Word and Byte swap – both word and byte is swapped.
Fault Enable • Check to write the Fault Value into the received data if this Read Command fails. This does not apply to write commands.
Fault Value • User-defined value to replace received data.