# Device Addressing – Offset

The Offset column of the Device Addressing tab defines offset within the device table to read or write the data block. The offset value should be entered in decimal (Dec), hexadecimal (Hex) or octal (Oct), depending on the PLC/MC series selected in the Settings tab, and the value of the Selected Device property:

- When using an FX Series PLC/MC, offset is defined in Oct for the following PLC/MC devices:
  - X - Input Relay
  - Y - Output Relay

  Offset is defined in Dec for the rest of the PLC/MC devices not listed above.

- When using an iQ-Q Series PLC/MC, the offset is defined in Hex for the following PLC/MC devices:
  - X - Input Relay
  - Y - Output Relay
  - B - Link Relay

  - W - Link Register

  Offset is defined in Dec for the rest of the PLC/MC devices not listed above.