Error Code 0x0012

Meaning

Unknown requested state change

Description

The ESM defines the following states. They are coded with fixed values (only lower (=right) nibble):

BOOT: AL Control = 0x03

INIT: AL Control = 0x01

PREOP: AL Control = 0x02

SAFEOP: AL Control = 0x04

OP: AL Control = 0x08

The fifth bit of the AL Control (left nibble is 1) is the “Error Acknowledge Bit”. If the slave is in AL STATUS = 0x14, i.e. ERROR SAFEOP the master acknowledges this by setting the Acknowledge bit.

Example: If any other value for AL Control than those specified are sent.

Current State (or state change)

Any

Resulting state

Current State + E

Solution

Do only request the defined states