Specifications

2 PCL-846 User's Manual
Description
PCL-846 ser ies cards provide f our inde pendent RS-422/485 ser ial
ports on a card. Each port has a 16C550 UART with an on-chip 16-
byte FIFO buffer for reliable, high-speed serial I/O. The UART
buffers data into 16-byte packets before putting it on the bus. This
drastically reduces the CPU load and avoids data loss when the system
is busy and cannot process the interrupt quickly. The UART is
especially useful for high speed serial I/O under Windows.
PCL-846 cards differ from cards in that they utilize on-board optical
isolators to protect your PC and equipment against damage from
ground loops, incr easing system r eliability in har sh en vir onments. To
further increase reliability, PCL-846B car ds inc lude sur g e pr otection
tec hnolo gy, pr otecting y our system fr om a br upt high v oltage surges
(up to 2000 V). T he PCL-846 ser ies has passed the CE test f or en vir on-
mental specif ications.
An RS-485 Network with Automatic Data Flow Control Using RS-232
Software
The RS-485 mode automatically senses the direction of incoming data
and switches its transmission direction accordingly. This feature
means your network looks and acts just like an RS-232 network.
Application software written for half duplex RS-232 can be used
without modification. Moreover, you can simply and quickly build an
RS-485 network with just two wires.
Features
• Four independent RS-422/RS-485 serial ports
• Transmission speeds up to 921.6 Kbps
• Shared/Independent IRQ settings between each of the 4 serial ports
• Wide IRQ selection: 3, 4, 5, 6, 7, 9, 10, 11, 12 or 15
• Supports standard DOS COM1, COM2, COM3, and COM4
• Suppor ts DOS/Windo ws 3.1, W indo ws 95, W indo ws NT (ICOM Utility)
•Pr ovides 1000 V
DC
isola tion (PCL-846A/846B onl y)