# Startup

Various initialisation processes of the ISG-MCP run through in the event of a cold start of the PLC program.

During this initialisation phase, AXSD is in the state 0 (INIT_STATE).

During this phase, all FBs of the MCP behave passively, i.e. they do not have write access to the HLI. If an FB sends a command before the initialisation phase has ended, e.g. as a result of initialisation of an "Enable" input with "TRUE", the FB reports the error ERR_PO_AX_TNA_INIT_STATE (P-ERR-44013).