Siemens SINUMERIK 840Di Function Manual page 978

Detailed description
2.7 Structure and functions of the basic program
An MCP or HHU failure is detected immediately after a cold restart even if no data have yet
been exchanged between the MCP/HHU and PLC.
The monitoring function is activated as soon as all components have signaled "Ready" after
powerup.
840D: MPI connection for HHU (not for new development)
Communications for HHU by PLC operating system and parameterization via SDB210.
Communication for the MCP is controlled from the PLC BP via the NCK and COM module as
described above.
Fig. 2-16
Relevant parameters (FB1):
Communication between the PLC and HHU is implemented through configuring and
subsequent loading of SDB210 (Global Data). To allow the basic program to access the
HHU data and implement HHU failure monitoring, the addresses set via global data must be
declared in FB1 parameters.
Relevant parameters (FB1)
MCP
Parameter settings are made via the
relevant parameters in FB1.
Status information (MCP1 and MCP2 see table Status information)
Available in
BHGStatRec
An error entry is also made in the PLC diagnostic buffer for timeouts,
2-66
840D: MPI connection for HHU
Bit No.
10
HHU
(parameterization via SDB210)
BHG = 1 (transfer via SDB210)
BHGIn (as parameterized in SDB210)
BHGOut (as parameterized in SDB210)
BHGStatRec (as parameterized in SDB210)
BHGTimeout (as parameterized in SDB210)
Description
Receiver: Timeout
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Power Line Basic PLC Program (P3)