Global Data Communication (Mpi Only); Table 3-3 Client And Server In S7 Communication, Using Connections With Unilateral / Bilateral Configuration - Siemens CPU 31 Series Technical Data Manual

Table 3-3
CPU
31xC >= V1.0.0
31x >= V2.0.0
31x >= V2.2.0
The user interface is implemented using standard function modules (FBs) from the standard
library of STEP 7, under communication blocks.
Reference
For further information on communication, refer to the
manual.
3.2.6

Global data communication (MPI only)

Properties
Global data communication is used for cyclic exchange of global data via MPI subnets (for
example, I, Q, M) between SIMATIC S7 CPUs (data exchange without acknowledgement).
One CPU broadcasts its data to all other CPUs on the MPI subnet. This function is
integrated in the CPU operating system.
Reduction ratio
The reduction ratio specifies the cyclic intervals for GD communication. You can set the
reduction ratio when you configure global data communication in STEP 7. For example, if
you set a reduction ratio of 7, global data are transferred only with every 7th cycle. This
reduces CPU load.
CPU 31xC and CPU 31x, Technical Data
Manual, 01/2006 Edition, A5E00105475-06
Client and server in S7 communication, using connections with unilateral / bilateral
configuration
Use in server mode for
connections with unilateral
configuration
Generally possible on
MPI/DP interface without
configuration of user
interface
Generally possible on
MPI/DP interface without
configuration of user
interface
Generally possible on
MPI/DP/PN interface
without configuration of user
interface
3.2 Communication services
Use in server mode for
connections with bilateral
configuration
Only possible with CP
and loadable FBs.
Only possible with CP
and loadable FBs.
Possible on PN
•
interface with
loadable FBs
or
with CP and loadable
•
FBs.
Communication with SIMATIC
Communication
Use as client
Only possible with CP
and loadable FBs.
Only possible with CP
and loadable FBs.
Possible on PN
•
interface with
loadable FBs
or
with CP and loadable
•
FBs.
3-9