GE C30 Instruction Manual page 59

CHAPTER 3: INSTALLATION DIRECT INPUT AND OUTPUT COMMUNICATIONS
Figure 3-23: Direct input and output single-channel connection
3
The interconnection for dual-channel type 7 communications modules is shown as follows. 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 UR4-Rx2, UR4-Tx2 to UR3-Rx2, UR3-Tx2 to UR2-Rx2, and UR2-Tx2 to UR1-Rx2 for the second ring.
Figure 3-24: Direct input and 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 and output data to
cross-over from channel 1 to channel 2 on UR2, set the setting to "Enabled" on UR2. This
DIRECT I/O CHANNEL CROSSOVER
forces UR2 to forward messages received on Rx1 out Tx2, and messages received on Rx2 out Tx1.
C30 CONTROLLER SYSTEM – INSTRUCTION MANUAL 3-25