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APPENDIX A: Pinning
Table 4. RS-485 pinning chart.
Pin Name
Description
TXA and TXB
Data received by the RS-232
↔
485/422 Converter at the
TXA=TX-
RS-232 port is transmitted out of the unit over twisted-
TXB=TX+
pair wires via these two outputs. The TX LED indicates
the state of these two leads. When the TXA lead is
positive with respect to the TXB lead (a “zero” being
transmitted), the TX LED is lit.
RXA and RXB
These are the received data inputs for the RS-485 port.
RXA=RX-
The status of these leads is monitored by the RX LED.
RXB=RX+
When the RXA lead is positive with respect to the RXB
lead (a “zero” is being received), the RX LED is lit.
