Manual

Doc.Id. HMSI-216-117
CM CANopen Module for SIMATIC S7-1200
Doc.Rev. 1.00
Chapter 6
6. CANopen Module Specification
6.1 NMT State Machine
The function of the CM CANopen Module for SIMATIC S7-1200 can be described as a state machine
with four states.
The module changes states upon reception of a request from the CANopen network, a hardware reset
or following a change in the PLC RUN/STOP state.
If the CM CANopen Module for SIMATIC S7-1200 is configured as a CANopen manager, the transi-
tions are initiated from the PLC. The module will either enter PRE-OPERATIONAL state or OPER-
ATIONAL state directly, depending on the configuration downloaded from TIA Portal to the PLC.
State Description
Initialization When the power is switched on, the module starts initializing. This is done in three steps:
basic initialization, reset application and reset communication.
The parameters are set to the so called power-on values, which are the default values or
the latest stored values. If parameter values are stored from a previous configuration, these
are used. If not, or if a restore_default command is issued, the parameters are reset to the
default values according to the communication and device profile specifications.
Pre-operational Once initialized, the module enters the pre-operational state. SDO (Service Data Object)
communication is allowed. A configuration application or configuration from CM CANopen
Module for SIMATIC S7-1200 can configure PDOs (Process Data Objects), device parame
-
ters and allocate application objects (PDO mapping).
Operational In the operational state all communication objects are active. Data is communicated
according to the configurations made. Not all SDO:s can be changed, as some information
e.g. an object may contain the application program that needs to stay fixed throughout
operation.
Stopped All communication is stopped, except node guarding and heartbeat, if active. From this
state any transition to another state is possible, depending on if a restart, reconfiguration or
reset of the module is wanted.
Initialization