UNI-TE Communication

UNI-TE Messaging

Schneider Electric's Modicon and Telemecanique products use the UNI-TE protocol for Ethernet communications. UNI-TE on TCP/IP uses:

the version of UNI-TE messaging that is applicable to the equipment (communication on the application layer)
TCP/IP (communications on Ethernet)

Two data exchange services are offered. The type of service depends on the type of server used. There are two choices:

synchronized data exchanges on the MAST task
data exchanges performed as a background task in the following modes:
- asynchronous server mode
- asynchronous client mode

Synchronous Exchanges

Synchronous exchanges take place in one of two modes:

server mode: All UNI-TE requests from the PLC are supported by the Ethernet module.
client mode: This type of exchange enables UNI-TE requests to be sent using the functions:
- READ_VAR
- WRITE_VAR
- DATA_EXCH
- ...

Asynchronous Exchanges

Asynchronous exchanges take place in one of two modes:

server mode: The consistency of the written or read data can be guaranteed (guarantees that the request is sent in one cycle) by setting the system bit %S91 to 1. In this configuration, a Jitter phenomenon of 1.5 ms can appear on the MAST task.
client mode: This service allows messages to be exchanged using the requests:
- READ_ASYN: enables up to 507 words (%MW) or 8112 bits (%M) to be read through the asynchronous messaging channel.
- WRITE_ASYN: enables up to 510 words (%MW) or 8160 bits (%M) to be written through the asynchronous messaging channel.