Connect Tech JB3, JB0, JB1, JB2 user manual Line Termination, RS-485/422 partial schematic

Chapter 4: Appendices – RS-485/422 Interface 4-11

Line Termination

You can use jumper blocks JC, JD, JE and JF to terminate and bias TxD ±, RxD ±, RTS ±, and CTS ± on the individual RS- 485/422 ports through jumper selectable 150 Ω fixed resistors.

Please refer to Figure 4 for a partial schematic of the RS-485/422 circuit for the Titan/cPCI and to Figure 1 for the locations of JC, JD, JE and JF.

Figure 4: RS-485/422 partial schematic

Titan/cPCI

RS-485/422 Line Bias/Termination

PCI 954

UART

			TxD +
TxD	150	Ω	JC5, JD5, JE5, JF5
			TxD -
DTR			10K Ω
	JA0, JA1, JA2, JA3
			+5 V
			1.8K Ω
			RxD +
RxD	JC3, JD3, JE3, JF3
			150 Ω
	JC4, JD4, JE4, JF4
			RxD -
			1.8K Ω
			RTS +
RTS	150	Ω	JC6, JD6, JE6, JF6

		RTS -
	1.8K Ω
	JC1, JD1, JE1, JF1	CTS +
CTS
	150	Ω

JC2, JD2, JE2, JF2

CTS -

1.8K Ω

+5 V

Note: Line bias/termination is jumper selectable

Titan/cPCI User’s Manual, ver. 0.00