Multiplexing OP connections / occupying internal CPU connection resources (S7-300) - STEP 7

Communications modules and network components

ft:publication_title
Communications modules and network components
Product
STEP 7
Version
V20
Publication date
11/2024
Language
en-US
Multiplexing OP connections / occupying internal CPU connection resources

Reference

Making special settings in the "Properties > General > Settings" parameter group

Depending on the CP type, you will see the option "Multiplex OP connections"

Multiplex mode

To connect TD/OPs and/or HMI devices, you can optimize the connection resources in the S7-300 CPU by allowing up to 16 such devices to communicate on a single CPU connection resource (multiplex mode).

If you do not use multiplex mode, the number of TD/OPs and/or HMI devices that can be used will depend on the number of available connection resources of the CPU used.

Use of internal CPU connection resources

Configured S7 connections via the CP use the same multiplex channel that you use in multiplex mode for HMI connections. This means that when you configure S7 connections, you already occupy one CPU connection resource.

Note

PG connections are not operated via the multiplexer; one connection resource is always occupied when you operate a PG.

Note

Addressing in multiplex mode

In multiplex mode, the rack/slot assignment of the CP must be specified instead of the rack/slot assignment of the CPU when assigning addresses for TD/OP/HMI connections.

Applications (for example ProAgent) that require block-related alarms (Alarm_S: SFC 17, SFC 18, SFC 19) are not supported in multiplex mode.