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TC2100 DM
User's Manual
Ver. 1.6
MNL-21000-01-16
Chapter 1 - Overview
Description
The TC2100 is a multi-drop fiber optic modem designed for dual ring (as known as counter rotating ring)
topology with self-healing capability as shown in Figure 1. It can also be configured for single ring topology
without self-healing capability. The TC2100 also has “Dual Master mode” ability, which can provide a
backup master unit when emergency condition occurs (see page 8 for details). The following description
applies only to dual ring configuration.
When connected to a SCADA host controller, the Master unit (TC2100) can broadcast its poll messages to
all the remote (Slave) units (also referred to as Slave units). The Remote Terminal Unit (RTU) connected
to the TC2100 (Slave) will respond only to the poll with that RTU's own specified ID (or address), which
is embedded in the poll message. The communication between the Master and Slave is transparent to
protocol and data rate; transmission can be full duplex provided only one RTU responds at a time.
The dual ring consists of an "A-Ring" and a "B-Ring." The A-Ring is the primary fiber optic ring and the B-
Ring is the backup fiber optic ring. Each Slave unit can detect any one of four possible cable breakage
conditions, referred to as "fault conditions," as shown in Figure 4. The TC2100 can detect ring breakage on
either the A-Ring or B-Ring. When a cable breakage occurs, both the upstream TC2100 (Master) and
downstream TC2100 (Slave) can detect the breakage and "wrap" around the data accordingly, as shown in
Figure 5.
The TC2100’s panel is equipped with multiple LED indicators and DIP switches. The LEDs indicate data
wrap or fault conditions such as "A2B" (or Loop A to B), "B2A" (or Loop B to A), or optic signal loss. The
DIP switches can activate the "Local Loopback" function or generate a pulsed electrical signal to simulate
a broadcast signal from the SCADA host. These features can be very useful during installation or when
troubleshooting the system. A dry contact relay alarm can be utilized to provided alarm status to the local
RTU. In the event that self-healing occurs, the local RTU can relay the alarm condition back to the SCADA
host controller, enabling the operator to easily determine and locate the problem site(s).
The electrical interface for the TC2100 can be RS-232, RS-422, or RS-485 (2 or 4-wire). Typical applications
include SCADA, process control, traffic control, and energy management. Due to the Self-Healing
capability, the TC2100 can provide maximum reliability for crucial SCADA applications.
Figure 1. Self-Healing Ring Topology
