Impulse 7108 - Manual (Page 10)

Technical Description
Sealevel Systems ULTRA COMM+I.LPCI Page 8
Technical Description
The Sealevel Systems ULTRA COMM+I.LPCI provides a PCI interface adapter with an isolated asynchronous
serial port providing a versatile interface, field selectable as RS-232 for modems, printers and plotters, as well as
RS-422/485 for industrial automation and control applications. 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 phenomenon that leads to data loss and the destruction of
communications interfaces.
The ULTRA COMM+I.LPCI utilizes the 16C850 UART. This chip features programmable baud rates, data
format, interrupt control and industry leading 128-byte FIFOs.
Connector Pin Assignments
RS-232 Signals (DB-25 Male)
Signal Name Pin # Mode
GND Ground 7
RD Receive Data 3 Input
CTS Clear To Send 5 Input
TD Transmit Data 2 Output
RTS Request to Send 4 Output
Technical Note: Please terminate any control signals that are not going to be used. The most common way to do this
is connect RTS to CTS. Terminating these pins, if not used, will help insure you get the best performance from your
adapter.
RS-422/485/530 Pin Assignments (DB-25 Male)
Signal Name Pin # Mode
GND Ground 7
RDB RX+ Receive Data Positive 16 Input
RDA RX- Receive Data Negative 3 Input
CTSB CTS+ Clear To Send Positive 13 Input
CTSA CTS- Clear To Send Negative 5 Input
TDB TX+ Transmit Data Positive 14 Output
TDA TX- Transmit Data Negative 2 Output
RTSB RTS+ Request To Send Positive 19 Output
RTSA RTS- Request To Send Negative 4 Output