Set section trace byte.
When hwEthernetFlagJ0Mode is set to j016ByteMode or j064ByteOrNullMode, this variable takes effect.
When hwEthernetFlagJ0Mode is set to j016ByteMode, this variable is up to 15 characters trace byte.
When hwEthernetFlagJ0Mode is set to j064ByteOrNullMode, this variable is up to 64 characters trace byte.