ADLINK Technology cPCI-3938, Manual

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Expansion/Isolation Module User Guide
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17
Specification
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6U CompactPCI form factor
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8 ports RS-232/422/485 selectable
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Isolation Voltage: 500 VDC
§
Max. 8 modules 64 ports for one cPCI-3938 controller module
§
Controller: FIFO type ST16C554
§
Baud Rate: Each port can be configured to 110 ~ 230,400 bps
§
Connector: REAR IO connector, REAR IO connector for port extension
§
Operating temperature: 0 ~ 60
°
C
§
Storage temperature: -10 ~ 70
°
C
§
Humidity: 5% ~ 95%, non-condensing
§
Power consumption: +5V @ 1400mA typical
For cPCI-6968, each port has two bits DIP switch to set for RS-232,
RS-422 or RS-485 interface. In RS-485 mode, we had auto data direction
function to maintain no local echo condition, but user may still need to
maintain just only one port to output data, so RS-485 mode must be used in
half-duplex transmission environment. For full-duplex transmission
environment, user may need to use RS-422 mode.
RS-422 interface application note:
RS-422 interface is used for point to point connection or multi-drop
application. We can use RTS & CTS signal to have hardware handshake
between two devices. But user may need to keep in mind that we can only
let one driver output signal to be active in one time, or you may let the driver
IC be burnt.
Even though we had put one 120 ohm terminator resistor in each input
signal pair, user may need to remove this terminator resistor for proper
operation.
Due to proper operation, user may not let one cable left in unconnected
condition. Because the crosstalk problem may let one transmit data signal
to be coupled to receive data input. This may lead wrong process in some
application environment.