Direct I/O Communications; Description - GE T35 Instruction Manual

3 HARDWARE

3.3DIRECT I/O COMMUNICATIONS

The T35 direct inputs/outputs feature makes use of the Type 7 series of communications modules. These modules are also
used by the L90 Line Differential Relay for inter-relay communications. The direct input/output feature uses the communica-
tions channel(s) provided by these modules to exchange digital state information between relays. This feature is available
on all UR-series relay models except for the L90 Line Differential relay.
The communications channels are normally connected in a ring configuration as shown below. The transmitter of one mod-
ule is connected to the receiver of the next module. The transmitter of this second module is then connected to the receiver
of the next module in the ring. This is continued to form a communications ring. The figure below illustrates a ring of four
UR-series relays with the following connections: UR1-Tx to UR2-Rx, UR2-Tx to UR3-Rx, UR3-Tx to UR4-Rx, and UR4-Tx
to UR1-Rx. A maximum of eight (8) UR-series relays can be connected in a single ring
Figure 3–19: DIRECT INPUT/OUTPUT SINGLE CHANNEL CONNECTION
The interconnection for dual-channel Type 7 communications modules is shown below. Two channel modules allow for a
redundant ring configuration. That is, two rings can be created to provide an additional independent data path. The required
connections are: UR1-Tx1 to UR2-Rx1, UR2-Tx1 to UR3-Rx1, UR3-Tx1 to UR4-Rx1, and UR4-Tx1 to UR1-Rx1 for the first
ring; and UR1-Tx2 to UR2-Rx2, UR2-Tx2 to UR3-Rx2, UR3-Tx2 to UR4-Rx2, and UR4-Tx2 to UR1-Rx2 for the second
ring.
Figure 3–20: DIRECT INPUT/OUTPUT DUAL CHANNEL CONNECTION
The following diagram shows the connection for three UR-series relays using two independent communication channels.
UR1 and UR3 have single Type 7 communication modules; UR2 has a dual-channel module. The two communication
channels can be of different types, depending on the Type 7 modules used. To allow the direct input/output data to 'cross-
over' from Channel 1 to Channel 2 on UR2, the
forces UR2 to forward messages received on Rx1 out Tx2, and messages received on Rx2 out Tx1.
GE Multilin
Tx
UR #1
Rx
Tx
UR #2
Rx
Tx
UR #3
Rx
Tx
UR #4
Rx
842006A1.CDR
Tx1
Rx1
UR #1
Tx2
Rx2
Tx1
Rx1
UR #2
Tx2
Rx2
Tx1
Rx1
UR #3
Tx2
Rx2
Tx1
Rx1
UR #4
Tx2
Rx2
842007A1.CDR
DIRECT I/O CHANNEL CROSSOVER
T35 Transformer Management Relay
3.3 DIRECT I/O COMMUNICATIONS

3.3.1 DESCRIPTION

setting should be "Enabled" on UR2. This
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