RTS and Auto Transceiver Control
In RS485 communications the driver must be enabled and disabled as needed, allowing all cards
to share a two wire cable. This card provides automatic control, where the driver is enabled when
data is ready to be transmitted. The driver remains enabled for the transmission time of one
additional character after data transfer is complete and then is disabled. The cards automatically
adjust their timing to the baud rate of the data.
The receiver is also normally disabled during RS485 transmissions.
CE Mark
If your card is CE-marked, it meets the requirements of EN50081-1:1992 (Emissions), EN50082-
1:1992 (Immunity), and EN60950:1992 (Safety).
Specification
Communications Interface
•
Serial Ports:
Shielded male D-sub 9-pin IBM AT style connectors
compatible with RS422 and RS485 specifications.
•
haracter length:
5, 6, 7, or 8 bits.
•
Parity:
Even, odd or none.
•
Stop Interval:
1, 1.5, or 2 bits.
•
Serial Data Rates:
Up to 115,200 baud, asynchronous. A faster range of
rates, up to 460,800 baud, is achieved by jumper
selection on the card. Type 16550 buffered UART.
Caution
The OUT2 bit of the UART must be set low for proper interrupt driven communication. This bit enables or
disables the interrupts and the card will not communicate if the bit is pulled high.
Differential Communication Mode
•
Multipoint:
Compatible with RS422 and RS485 specifications. Up to
32 drivers and receivers allowed on line. Serial
communications ACE used is type 16550.
Driver/Receivers used are type 75176.
•
Receiver Input Sensitivity:
+200 mV, differential input.
•
Common Mode Rejection:
+12V to -7V
•
Transmitter Output Drive Capability:
60 mA.
Manual PCI-ICM-2S
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