Glossary - Siemens SIMATIC EMS400S Operating Instructions Manual

Glossary

ACK bit
Acknowledgment bit that is mapped to the PII and PIO of the plant segment controller and
carrier controller.
The ACK bit is used to toggle the data flow on the → RAIL between the data to be
acknowledged and data that is not acknowledged in the process image.
Bridge bit
The bridge bit is used by EMS carriers to reliably recognize the segment bridges. To
accomplish this, the parity bit configured in the data frame is formed in → 2 bridge bits as 01
or 10. The bridge bits 11 mean there is a segment bridge. The bridge bit is transferred via →
RAIL.
Broadcast
The term broadcast denotes the transmission of data packets from a source station to all
other nodes on the data network.
Transmission to an → EMS with the carrier controller means the broadcast of dispatch data
from one → plant segment controller to all → EMS carriers of a → plant segment.
C data
Data that is sent the interface from the → PSB-C module over the → RAIL interface.
Carrier controller
The control component of the EMS400S carrier controller consisting of a CPU and a → PSB-
C module. The carrier controller controls the → EMS carrier.
Contact conductor
Electrical part of the EMS rail. The EMS rail is equipped with 6 contact conductors. The
contact conductors are used to supply power to the → EMS carrier and the data
communication. The two contact conductors for data communication are called → RAIL.
Control data
Data that controls → user data traffic between the PSB modules. The control data are resent
with each → data subframe.
Carrier controller
Operating Instructions, 09/2013, A5E03474162-02
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