DL8000 Preset Instruction Manual
3-38
Modules
Revised February-2016
about noise. If you suspect noise related data errors, it may be necessary
to either reroute the cable or eliminate the source of the impulse noise.
Multi-pair, PVC 24 AWG telephone cables have an attenuation of
approximately 8 to 10 dB/100 m at 200°C (392°F). The attenuation of
PVC insulted cable varies significantly with temperature. At
temperatures greater than 400°C (752°F), use plenum rated cables to
ensure that cable attenuation remains within specification.
When connecting two twisted-pair MAUs (Medium Attachment Units)
or repeaters together over a segment, wire the transmit data pins of one
eight-pin connector to the receive data pins of the other connector, and
vice versa. There are two methods for accomplishing 10BASE-T
crossover wiring:
Special cable.
Wire the 10BASE-T crossover inside the hub.
For a single segment connecting only two devices, provide the signal
crossover by building a special crossover cable, wire the transmit data
pins of one eight-pin connector to the receive data pins of the other
connector, and vice versa. See
Figure 3-40
.
Signal
Signal
Pin 1 TD+
Pin 1 TD+
Pin 2 TD–
Pin 2 TD–
Pin 3 RD+
Pin 3 RD+
Pin 6 RD–
Pin 6 RD–
Figure 3-40. 10BASE-T Crossover Cable
3.3.5 EIA-232 (RS-232) Serial Communications
The built-in EIA-232 (RS-232), the LOI, and the communication
modules meet all EIA-232 (RS-232) specifications for single-ended,
asynchronous data transmission over distances of up to 15 meters (50
feet). EIA-232 (RS-232) communication provides transmit, receive,
and modem control signals. The LOI port also meets EIA-232D (RS-
232D) specifications.
The EIA-232 (RS-232) communications have the following
communication port designations in ROCLINK 800.
LOI
– Local Port EIA-232 (RS-232D). Refer to
Section 3.3.2, Local
Operator Interface
.
Built-in
– Comm2 EIA-232 (RS-232C).
Module
– Comm3 to Comm5 EIA-232 (RS-232C).