This function performs a combination of one read operation and one write operation in a single MODBUS transaction. The write operation is performed before the read.
Holding registers are addressed starting at zero. Therefore holding registers 1-16 are addressed in the PDU as 0-15.
The request specifies the starting address and number of holding registers to be read as well as the starting address, and the data to be written.
To configure this step open the Edit Step window from Sequence editor.
In the configuration dialog box, you can change the following settings:
· Connection Name: connection used to communicate with the device.
Write Multiple Registers part of this dialog box:
· Address: starting address of the registers to be set.
· Nb Registers: Number of register to write.
· Index: Index of the first register visible in the table.
· Registers Value: value of registers to write (1 to 121 registers) from the starting address.
Read Multiple Registers part of this dialog box:
· Address: starting address of the input registers to be read.
· Nb Registers: number of holding registers (1 to 125 registers) to read from the starting address.
The value of the registers is stored in Step.Result.Read.RegistersValue
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Note Please read Execution Trace and Steps Variables chapter to learn more about accessing configuration of this step and how to access data read. |
See Also
