ARCNET PCX Series Legacy Product

ARCNET PCX Series

Product Overview

  • Utilizes COM90C65 ARCNET® controller
  • Interfaces ARCNET with XT/AT (ISA) bus computers
  • One-third height PC board
  • Supports coaxial, twisted-pair, or glass fiber optic cabling
  • Supports 16 kB memory mapping, minimizing memory addressing conflicts
  • Provides socket for 8 kB auto-boot ROM
  • Node address switch accessible without removing the PCX from computer
  • CMOS design for low-power consumption

The PCX Series of Network Interface Modules (NIMs) links XT/AT (ISA) compatible computers with the ARCNET Local Area Network (LAN). The series is perfect for XT bus ISA compatibility.

The PCX incorporates the COM90C65 ARCNET controller chip, and the module works with either XT or AT (ISA) backplanes. Jumpers are used to set the interrupt and the base addresses for memory and I/O.

Each PCX module has two LEDs on the board for monitoring network operation and bus access to the module. It also has an external DIP switch so that node addresses can be easily reassigned without removing the module. Interrupt lines are jumper selectable.

The PCX Series is available in five cabling options. The PCX-CXS supports coaxial cable in a star configuration. The PCX-CXB accommodates coaxial cable in a bus configuration. Both the PCX-TPS and PCX-TPB support twisted-pair, respectively in a star and bus configuration.The PCX-FOG accommodates duplex glass fiber optic cable with ST connectors.

The PCX Series is now an end-of-life product. Therefore, it is not recommended for new installations.

Replacement Information

The PCX Series of NIMs has no drop-in replacement. This series used the COM90C65 ARCNET controller chip that is no longer available. Second-hand PCX NIMs might be obtained from vendors of used ARCNET equipment, but Contemporary Controls does not know of any such vendors.

For users willing and able to modify their application-layer software, currently available NIMs could possibly substitute. PCX20 NIMs fit in ISA slots and use the COM20020 ARCNET controller chip. PCI20U NIMs fit in PCI slots and use the COM20022 ARCNET controller chip. Due to the differences between the COM90C65 chip and the COM20020/22 chips, ARCNET functionality will change. If you are thinking of replacing a PCX NIM with a NIM that uses the COM20020/22 chip, note the following important considerations:

  • Memory mapping can no longer be used for data operations because a COM20020/22 chip transfers data through its I/O space.
  • 16-bit data operations are not supported by our drivers, but 16-bit operation is possible for those writing their own drivers.
  • Although PCX20 and PCI20 software drivers are available, they alone will not provide an upgrade. A software rewrite will still be required.
  • Contemporary Controls does not rewrite software for users.

PCX20 NIMs have free null-stack drivers available for Windows NT/95/98/ME/2000/XP use of NDIS drivers is strongly discouraged. Each downloadable driver file is actually a set of files which includes a programmer guide and sample applications. PCX20 drivers, more driver information and utilities are available here.

PCI20U NIMs have free null-stack drivers available for Windows NT/95/98/ME/2000/XP/Vista use of NDIS drivers is strongly discouraged. Each downloadable driver file is actually a set of files which includes a programmer guide and sample applications. PCI20U drivers, more driver information and utilities are available here.

PCX20 and PCI20U NIMs provide most of the same transceiver options as PCX NIMs except that the twisted-pair star option is no longer supported and fiber ports are no longer supported. If you need to replace a PCX-CXS, you should use a 93-ohm terminator attached to a Tee on the BNC connector of the replacement NIM. If you need fiber connectivity for a PCX20 or PCI20U NIM, you should use an AI Series hub for the media conversion.