Black Box IC108AE, IC109C, IC109AE, IC109A-R2, IC108C manual Pin Name Description

	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.

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