Omega Vehicle Security ISA RS-422 - Manual (Page 14)

Technical Description
OMG-ULTRA-SIO Page 10
Technical Description
The OMG-ULTRA-SIO provides the PC with two additional ground isolated RS-
422/485 (P/N 3189) or two non-isolated RS-422/485 (P/N 3089) serial ports for
terminals, modems, printers, etc. Isolation is important in installations where the
equipment being connected to the PC is either far from the PC, or on a different
power transformer circuit. Ground loop current is a commonly neglected and
misunderstood phenomena that leads to data loss and the destruction of
communications interfaces. The OMG-ULTRA-SIO isolated boards provide up
to 500 volts DC of isolation.
The OMG-ULTRA-SIO utilizes the 16550 UART. This chip features
programmable baud rate, data format, interrupt control and a 16 byte input and
output FIFO. A full array of UART upgrades is also available offering larger
FIFO’s. Contact technical support for details.
Features
•
Automatic RS-485 driver enable/disable allows card to appear to be RS-232
requiring no additional drivers
•
‘PAL’ option allows for unique OEM address selection
•
‘Shareable’ IRQs allow more than one port to share a single IRQ providing a
polling type driver is used.
•
IRQs 2/9-7, 10, 11, 12, 14, 15 supported
•
16550 buffered UARTs Standard
•
16 Bit address decode allows for easier integration
Connector Pin Assignments (DB 9 MALE)
Signal Name Pin # Mode
GND Ground 5
TX + Transmit Data Positive 4 Output
TX- Transmit Data Negative 3 Output
RTS+ Request To Send Positive 6 Output
RTS- Request To Send Negative 7 Output
RX+ Receive Data Positive 1 Input
RX- Receive Data Negative 2 Input
CTS+ Clear To Send Positive 9 Input
CTS- Clear To Send Negative 8 Input