2-2 Chapter 2: Hardware Installation
RS-485/422 Line Interface
The Titan/cPCI adapters come with a jumper selectable RS- 485/422 electrical line interface for each port. The RS-485/422 electrical interface is a reliable high-speed serial link that offers superior noise immunity and multi-drop network connectivity. The RS-485/422 electrical interface is also a superset of the RS- 422 electrical interface. Titan/cPCI adapters offer full RS- 485/422 support in hardware. The support is:
Full Duplex Mode
In this mode, TxD & RxD are active all the time. This mode is typically used in point to point situations much like RS-232. Please refer to Appendix D: RS-485/422 Line Interface for the jumper settings associated with this function.
Half Duplex Mode
In this mode the TxD line driver is enabled only when data is transmitted and RxD is disabled when data is being transmitted. This mode is typically used in either point to point "2 wire" connections OR in multi-drop "2 wire" bussed connections. Please refer to Appendix D: RS-485/422 Line Interface for the jumper settings associated with this function.
Multi-drop Slave Mode
In this mode the TxD line driver is enabled only when data is transmitted and RxD is enabled all the time. This mode is typically used in multi-drop "4 wire" connections. Please refer to Appendix D: RS-485/422 Line Interface for the jumper settings associated with this function.
Line Termination
You can terminate and bias TxD ±, RxD ±, RTS ±, and CTS ± on the individual RS-485/422 ports through jumper selectable 150
Ωfixed resistors. Please refer to Appendix D: RS-485/422 Line Interface for the jumper settings associated with this function.
Titan/cPCI User’s Manual, ver. 0.00
