Channel X - Modbus Master view parameter

In
Device definition
, when
Channel
X
 is set to
Modbus Master
, the
Channel
X
 - Modbus Master
 view includes these parameters:
Parameter
Description
up
Moves the selected commands up in the list.
IMPORTANT
: If you move the command up, adjust the program to reflect the new command location. Otherwise, a return error occurs upon validation.
down
Moves the selected commands down in the list.
IMPORTANT
: If you move the command down, adjust the program to reflect the new command location. Otherwise, a return error occurs upon validation.
Command
Indicates the command being configured.
Communication Method
Specifies the communication method for the command.
Available options are:
  • Disabled
     (default)
  • Continuous
  • Conditional
Tip: Parameters are unavailable when the communication method is disabled.
Data Type
Specifies the data type for the command. Available options are:
  • BOOL
  • INT
  • REAL
Function Code
Specifies the function of the command. Available options depend on
Data Type
:
  • Read Coils
    . Used to read from 1 to 2000 contiguous status of coils in a remote device.
  • Read Discrete Inputs
    . Used to read from 1 to 2000 contiguous status of discrete inputs in a remote device.
  • Write Single/Multiple Coils
    . Used to write a single output to either ON or OFF in a remote device.
  • Read Holding Registers
    . Used to read the contents of a contiguous block of holding registers in a remote device.
  • Read Input Registers
    . Used to read from 1 to 125 for INT or 1 to 62 for REAL contiguous input registers in a remote device.
  • Write Single/Multiple Registers
    . Used to write a single holding register in a register in a remote device.
Slave Address
Specifies the node address of the Modbus Slave device. Valid value is 0–247.
Tip: For broadcast command, set
Slave Address
 to 0.
Modbus Address Offset
Specifies the offset to the actual Modbus Address. Valid value is from 0 through 65535.
Data Length
Specifies the number of data points being read. The valid data length values depend on the
Data Type
 and the
Function Code
.
Poll Interval
Specifies the number of seconds between each time the command is executed when in
Continuous
 mode.
For example, if the
Poll Interval
 is set at 10, the Modbus Master waits 10 seconds before executing the command again.
Valid value is from 0 through 32767.
Tip: This parameter is unavailable when the
Communication Method
 is
Conditional
.
Swap Mode
Specifies the arranging of the received/send data from the Modbus Slave. Possible available options:
  • No Change
     (ABCD = ABCD)
  • Word Swap
     (ABCD = CDAB)
  • Byte Swap
     (ABCD = BADC)
  • Word and Byte Swap
     (ABCD = DCBA)
Fault Enable
Determines whether or not to overwrite the received data with a
Fault Value
 if the read command fails.
Select the checkbox to overwrite the received data with the
Fault Value
.
Tip: This parameter is unavailable when the
Function Code
 is a write command.
Fault Value
Specifies the value to replace the received data.
Remaining connection data
Displays the remaining connection data as the command list is configured.
When Connection 1 is not able to fit the next command, Connection 2 is used, and remaining Connection 1 data is set to 0.
When Connection 2 is not able to fit all the commands, remaining Connection 2 data shows how many bytes (in negative number) cannot fit.
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