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PCL-740 User's Manual
Description
The PCL-740 card enables RS-232, RS-422, RS-485 or current-loop
serial communication for applications in difficult environments. You
can configure its port to RS-232, RS-422, RS-485 or current-loop
using on-board jumpers.
The card features a 16C550 UARTs (with on-chip 16-byte FIFO)
making serial I/O more reliable. By buffering data into 16-byte
packets before putting it on the bus the UART drastically reduces the
CPU load. This makes the PCL-740 especially suitable for high
speed serial I/O applications and applications under MS Windows.
In RS-485 mode, the PCL-740 automatically senses the direction of
incomming data and switches its transmission direction accordingly.
Therefore no handshaking signal (e.g. RTS signal) is necessary. This
feature lets you simply and quickly build an RS-485 network with
just two wires. More importantly, application software previously
written for half duplex RS-232 environments, can be used without
modification.
Summary of Contents for PCL-740
Page 1: ...PCL 740 SerialCommunication RS 232 422 485 Current Loop InterfaceCard ...
Page 4: ...Chapter 1 Introduction 1 1 Introduction C H A P T E R ...
Page 9: ...6 PCL 740 User s Manual ...
Page 10: ...Chapter 2 Hardware Installation 7 2 Hardware Installation C H A P T E R ...
Page 20: ...Appendix A Register structure and format 17 A Register structure and format A P P E N D I X ...
Page 27: ...24 PCL 740 User s Manual ...
Page 28: ...Appendix B PC I O Address Assignments 25 B PC I O Address Reference A P P E N D I X ...
