BB-VESP211x Serial Servers
:
RS-485
The RS-485 interface supports 2-wire or 4-wire operation.
When configured for 4-wire operation the connection supports two signal pairs: TDA (-), TDB (+), RDA (-
), RDB (+) and GND. This makes full-duplex operation possible. The data lines are differential pairs (A &
B) in which the B line is positive relative to the A line in the idle (mark) state. Ground provides a common
mode reference.
When configured for 2-wire operation the connection supports one signal pair: Data A (-) and Data B (+)
signal channels using half-duplex operation. The data lines are differential with the Data B line positive
relative to Data A in the idle (mark) state. Ground provides a common mode reference.
Note: Refer to Appendix D for connector pinout information.
Figure 3.1 BB-VESP211x Connections
CONNECTING BB-VESP211X SERIAL SERVERS TO A NETWORK
ETHERNET CONNECTION (10BASET/100BASETX)
The Ethernet connection uses a standard RJ45 connector. A standard network cable is connected from
the serial server to a network drop. PCs configuring and/or communicating with the serial server are also
connected to the network.
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