MESA ELECTRONICS 4I23 QUAD SERIAL FEATURES: QUAD RS-232, RS-422 or 2+2 RS-485 capable outputs Uses 16C550 FIFOed UARTS Access to all AT bus interrupts RS-232 power generated on card Shared interrupt capability Low power - all CMOS Small size Made in USA - local support 2 year warranty The 4I23 is a low cost, four channel serial port addresses so that no extra I/O port locations are card on a stackable PC/104 bus card. The 4I23 is required, and complete COMX type serial port available in three versions: quad RS-232, quad compatibility is maintained. RS-422, and a model with two RS-232 and two The RS-422 ports have one handshake-in and RS-422 channels. one handshake-out line. The RS-422 drivers can The 4I23 uses 16C550 type FIFO'ed UART's. be software enabled and disabled for bus (RS- These UART's have built-in 16 byte receive and 485) type applications. RTS is used for RS-422 transmit FIFO's. The 16 character FIFO's reduce enable / disable. Enable polarity can be chosen interrupt overhead and allow higher data rates such that the driver is enabled or disabled at without losing characters. The receive FIFO's also power up. Jumper selectable 125 Ohm RS-422 increase the allowable interrupt latency. This is termination is provided on card. especially important when using programs like Serial port connectors are 10 pin headers that WINDOWS that disable interrupts for match 9 pin AT type serial port pinout when the comparatively long periods of time. flat cable from the header is terminated with an Unlike many serial cards, the 4I23 is IDC type 9 pin subminiature D connector. RS-422 implemented with the 16 bit bus connector so that pinout is similar to EIA RS-449 9 pin D secondary each of the four serial ports on the 4I23 can use channel pinout. any of the 11 available AT bus interrupts. Serial port addresses are set with a PAL The 4I23 also has an shared interrupt device. Eight different sets of port locations can capability. The four serial port interrupts can be be selected by option jumpers. The decode PAL logically or'ed to a common interrupt. The or'ed is socketed to simplify changing the default decode set. interrupts are individually maskable. The interrupt status of all four channels is readable at a single The 4I23 requires only +5V for operation, as port location to allow quick response to the shared all RS-232 power is generated on card. All CMOS interrupt. All additional I/O necessary to technology keeps power dissipation to a implement the shared interrupt logic uses aliased minimum. MESA 1/94 MESA ELECTRONICS 4I23 QUAD SERIAL 4I23 CONNECTOR PINOUT HDR PIN DSUB PIN RS-232 FUNCTION RS-422 FUNCTION 11DCDGND 26DSRRXDB 32RXDNC 47RTSRTSA 53TXDTXDA 68CTSCTSA 74DTRRXDA 89RITXDB 95GNDGND 10NC+5VPOWER+5VPOWER DEFAULT PORT LOCATIONS COM13F8HCOM5100HCOM9120H COM22F8HCOM6108HCOMA128H COM33E8HCOM7110HCOMB130H COM42E8HCOM8118H 4I23 SPECIFICATIONS: Min Max Units Notes POWER REQUIREMENTS: Supply voltage 4.5 5.5 V Supply current (4I23A) ---- 100 mA No interface loading Supply current (4I23B) ---- 150 mA No interface loading Supply current (4I23C) ---- 200 mA No interface loading ENVIRONMENTAL: o Temperature range -C version 0 +70 C o Temperature range -I version -40 +85 C Relative humidity 0 90 Percent Non-Condensing ORDERING INFORMATION: 4I23A 4I23 QUAD SERIAL WITH 4 RS-232 PORTS 4I23B 4I23 QUAD SERIAL WITH 2 RS-422 and 2 RS-232 PORTS 4I23C 4I23 QUAD SERIAL WITH 4 RS-422 PORTS Add -I to specify industrial temperature range MESA ELECTRONICS -- 4175 Lakeside Drive, Suite 100, Richmond, CA 94806 PHONE (510) 223-9272 -- FAX (510) 223-9585