Introduction
The embedded Ethernet I/O scanner service in the M580 CPU scans network modules.
However, you can enable the CPU’s scanner service as an EtherNet/IP adapter (or local slave). When the local slave functionality is enabled, network scanners can access CPU data that is mapped to local slave assembly objects in the CPU program.
The CPU’s scanner service continues to function as a scanner when it is enabled as an EtherNet/IP adapter.
To get data from the primary CPU, make the connection to the Main IP address of the CPU.
The CPU’s scanner service supports up to 16 instances of local slaves (Local Slave 1 ... Local Slave 3). Each enabled local slave instance supports these connections:
one exclusive owner connection
one listen-only connection
Process Overview
These are the steps in the local slave configuration process:
Stage |
Description |
|---|---|
1 |
Enable and configure the CPU’s scanner service as a local slave. |
2 |
Configure local slave instances in the scanner service. (Local slave instances correspond to each enabled local slave that is scanned.) |
3 |
Specify the size of local slave input and output assemblies in the scanner service. (Use sizes that match the input and output sizes of the enabled local slave.) |
Implicit and Explicit Messaging
In its role as an EtherNet/IP adapter, the CPU scanner services responds to these requests from network scanners:
implicit messages: Implicit messaging requests are sent from a network scanner device to the CPU. When the local slave functionality is enabled, network scanners can perform these tasks:
read messages from the CPU’s scanner service
write messages to the CPU’s scanner service
Implicit messaging is especially suited to the exchange of peer-to-peer data at a repetitive rate.
explicit messages: The CPU’s scanner service responds to explicit messaging requests that are directed to CIP objects. When local slaves are enabled by the CPU, explicit messaging requests can access the CPU’s scanner service CIP assembly instances. (This is a read-only function.)
Third-Party Devices
If the CPU’s scanner service that communicates with the local slave can be configured using Control Expert, use DTMs that correspond to the CPU to add those modules to your configuration.
Third-party EtherNet/IP scanners that access the local slave assembly instances through the CPU’s scanner service do so with respect to the assembly mapping table. The CPU’s scanner service is delivered with its corresponding EDS file. Third-party scanners can use the contents of the EDS file to map inputs and outputs to the appropriate assembly instances of the CPU’s scanner service.