Measurement Computing PCI-COM422/485 - Manual (Page 19)

15
5. SPECIFICATIONS
Typical for 25°C unless otherwise specified.
P OWER CONSUMPTION
+5V
PCI-COM422/485 240mA typ.
PCI-COM422/485-2 250mA typ.
C OMMUNICATIONS SECTION
Number of Ports
PCI-COM422/485 1
PCI-COM422/485-2 2
Port Type RS422 or RS485 (software selectable)
UART 16C550
Data Rate Up to 460 kbaud, software selectable
Miscellaneous RS485 mode is software programmable for RTS Enable,
DTS Enable or Automatic Enable
DB9F female 9-pin D connector
I NPUT /O UTPUT SECTION
Data Transceiver type SP491
Data Rate 5Mbps min.
Data Transceiver Output Characteristics
Vol 0.4V max. (Iout= +4mA)
Voh
3.5V min. (Iout= -4.0mA)
Differential Output Voltage GND to Vcc (unloaded)
Short Circuit Current
±250mA
Propagation Delay 30ns typ. (tplh/tphl)
Driver Enable to Output High
40ns typ.
Driver Enable to Output Low 40ns typ.
Driver Disable Time to Low40ns typ.
Driver Disable Time to High
40ns typ.
Data Transceiver Input Characteristics
Vil 0.8V max.
Vih 2.0V min.
Maximum Input Voltage
±14V
Differential Threshold Voltage ±0.2V
Input Current 1mA (Vin = 12V)
-0.8mA (Vin=-7V)
Propagation Delay 90ns typ. (tplh/tphl)
Receiver Enable to Output Low
20ns typ.
Receiver Enable to Output High 20ns typ.
Receiver Disable from Low 20ns typ.
Receiver Disable from High 20ns typ.