Siemens 500 NIM User Manual
TIWAY I Overview
1-2
SIMATIC TIWAY I Series 500 NIM User Manual
1.1
TIWAY I System Overview
TIWAY I is an industrial Local Area Network designed to satisfy today’s
factory and plant requirements for data acquisition and control of
manufacturing processes. It is a significant enhancement of the Siemens
“Local Line,” which has supported the PM550 Programmable Controllers
and DS 990 computer products since 1980.
factory and plant requirements for data acquisition and control of
manufacturing processes. It is a significant enhancement of the Siemens
“Local Line,” which has supported the PM550 Programmable Controllers
and DS 990 computer products since 1980.
The TIWAY I network provides a reliable and flexible communication
architecture. Two communication media options are available:
architecture. Two communication media options are available:
•
RS-232-C/423 — provides modem interface for large geographic
coverage.
coverage.
•
Local Line — provides high noise immunity for networks up to 25,000
feet (7620 meters).
feet (7620 meters).
Redundancy is supported for either choice of media. TIWAY I uses
High-level Data Link Control (HDLC) protocol with CRC-16 error-checking
and message-length error-checking, providing reliable network
communication.
High-level Data Link Control (HDLC) protocol with CRC-16 error-checking
and message-length error-checking, providing reliable network
communication.
Throughout this manual, the following networking terms are used.
•
Primary — the HDLC network manager
•
Secondary — the device operating as an HDLC secondary slave (NIMs,
UNILINK
UNILINK
Secondary Adapters)
•
Attached device — controller, robot, etc. (Siemens controller connected
to the NIM, robot connected to a UNILINK Secondary Adapter)
to the NIM, robot connected to a UNILINK Secondary Adapter)