E17 Endianness

Definition

Sets the byte order for multi-byte data during RX (flow meter response) transmission. Options: Big Endian, Little Endian, Register Swap, or Byte & Register Swap. Default: Big Endian.

This setting does not affect Modbus ID, function code, CRC, or single-byte data.

For example, when returning flow and flow rate data, the flow value (e.g., 1000 decimal = 0x00007A44) is still sent before the flow rate. However, the order of the four bytes representing 1000 changes depending on the selected format. (The diagram below shows each diamond representing one byte.)

Example

The following shows an example of using Function Code 04 to request the flow meter to return instantaneous flow (FS + value) and totalized flow (TF + value). (Each diamond in the diagram below represents one byte.)

• First row: Command sent from the Master. This is not affected by this setting. For details, refer to Modbus Function Code 04.

• Second row: Response from the flow meter with Big Endian configured. From left to right, bytes 0x01–0x08 and CRC1–CRC2 are not data and are unaffected by this setting. The order of instantaneous flow (FS + value) and totalized flow (TF + value) in the response is also unchanged.

  • Because Big Endian is selected, the four bytes of instantaneous flow (FS3 → FS0) are sent starting with FS3.

  • The four bytes of totalized flow (TF3 → TF0) are sent starting with TF3.

• Third row: Response from the flow meter with Little Endian configured. From left to right, bytes 0x01–0x08 and CRC1–CRC2 are not data and are unaffected by this setting. The order of instantaneous flow (FS + value) and totalized flow (TF + value) in the response is also unchanged.

  • Because Little Endian is selected, the four bytes of instantaneous flow (FS0 → FS3) are sent starting with FS0.

  • The four bytes of totalized flow (TF0 → TF3) are sent starting with TF0.

Modbus Converter for different formats

Byte Order Explanation

Assume a 32-bit value is composed of 4 bytes (A = most significant byte, D = least significant byte) and stored in two 16-bit registers. ($\mathbf{Reg1 = A B}$, $\mathbf{Reg2 = C D}$)。

Type	Transmission Order (Hex)
Big Endian	$\mathbf{A~B~C~D}$
Little Endian	$\mathbf{D~C~B~A}$
Mid Big Endian	$\mathbf{C~D~A~B}$
Mid Little Endian	$\mathbf{B~A~D~C}$

Notes

1. E17 Endianness can be modified via RS485.

2. The setting must match exactly with the Master’s configuration.

3. For details, see the RS485 and Modbus RTU Settings section.

Operation Procedure

Button Functions (Click to Expand)

The main unit has four buttons. The bottom line (Line 3) of the LCD displays the current function of each button. Under normal operation, the button functions are as follows:

• Blue Button - Leftmost button: Return, exit, or save settings.

Gray Arrow Buttons:

• Left Gray Button: Page up, increase value, or select item

• Right Gray Button: Page down, decrease value, or select item

• Orange Button: Rightmost button: Enter settings, edit, or confirm selection

Do not hold buttons for extended periods to avoid damage.

Button functions may change depending on the operation context to improve usability or prevent accidental presses.

E17 Endianness Setting Steps
• From the main screen (green backlight), 
  press Orange Button (Setup) to enter settings (orange backlight).
• Use Gray Arrow Buttons to select E. Commute, press Orange Button (Enter).
• Use Gray Arrow Buttons to select E17 Endianness , press Orange Button (Enter).
• Use Gray Arrow Buttons to choose the options. 
• Press Orange Button (Set) to confirm.
• Press Blue Button (ESC) to return to the main screen (green backlight).

E17 Options, RS485 Values, Read/Write Commands, and Formats

Opitons	Description	RS-485 Value
Big Endian (Default)		0
Little Endian		1
Mid Big Endian	Register Swap	2
Mid Little Endian	Byte & Register Swap	3

Refer to the Read/Write Memory List for the Modbus command format. This parameter uses the Int16 data format.