Technical Description
Technical Description
The OMG-ULTRA-SIOprovides 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-SIOisolated boards provide up to 500 volts DC of isolation.
The OMG-ULTRA-SIOutilizes 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 |
