Sub-index does not exist (Register 0007)

What does 03 mean?

An attempt was made to access a sub-index of an array parameter through Holding Register 0007 that does not exist. This indicates an incorrect index number was provided when referencing an element within an array-type parameter, leading to an invalid memory access.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Correct the index value in Holding Register 9 before attempting to access the array parameter again.

2. 4

   Ensure the Modbus request's structure correctly addresses array parameters, as they often require separate index registers.