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$297.00 (USA and Canada only)

Availability: In stock
ISA Bus To Pamux Bus Adapter

Production Specification

The AC28 adapter card links Opto 22 I/O to a computer for PC-based control using the Pamux protocol.

This card is compatible with the ISA bus and therefore is not recommended for new development. It has been replaced by the PCI-AC51 adapter card, which is compatible with the PCI bus.

The AC28 is compatible with the following brains (I/O processors):
  • B4 (G4 or Quad Pak digital I/O)
  • B5 (G4, G1, Quad Pak, or integral digital I/O)
  • B6 (G1 analog I/O)
For stations on a Pamux bus to operate correctly, both ends of the bus must be terminated. The host computer and the last Pamux station on the bus are the only devices that should be terminated. Because termination resistors are built into the AC28, the host computer is automatically terminated. Use part number TERM 1 or TERM 2 (shielded cable) for the last Pamux station. See the Pamux User's Guide for more details.

Use the AC28 and PCI-AC48 Adapter Card Toolkit with this card.


Power requirements

5 VDC ±0.1 V @ 1.5 A

Operating temperature

0 °C to 60 °C

Relative humidity

0% to 95%, non-condensing


50-pin male header connector


Up to 500 feet total length


AC28 Installation Notes

This document describes how to install the AC28 adapter card.

Pamux User's Guide

This manual provides all the information you will need to set up and use a Pamux system. It features complete descriptions of all Pamux components, including the B4, B5, and B6 brain boards and the AC28 and AC36 adapter cards.

Opto 22 RoHS 3 Statement of Compliance - Restriction of Hazardous Substances

This document is a statement of compliance with the EU Directive 2015/863/EU, Restriction of Hazardous Substances (RoHS 3). This document lists Opto 22 products that comply with the substance restrictions of the RoHS 3 directive.

CE Declaration: Component

This document is the Manufacturer's Declaration for the listed products as mentioned in the attachment - to which this confirmation refers - that they are in accordance with the mentioned European, international and/or national standards and regulations.

AC28 and PCI-AC48 Adapter Card Toolkit

For AC28 and PCI-AC48 adapter cards. For Microsoft Visual Basic or Microsoft Visual C++ Users.

NOTE: This toolkit also includes files for the AC5 adapter card. Do not use these files; they have been replaced. For AC5 cards, you can use version R5.0b of the PC-Based Direct I/O SDK. The filename is PC_Based_Direct_IO_SDK_R5.0b.exe, and it can be downloaded from Opto 22's FTP site.

AC28 Pamux Adapter Card Support

Includes a support archive for the AC28 adapter card. (Support is for existing systems only; this card is not recommended for new development. Use the PCI-AC51 adapter card instead.)

IMPORTANT: This toolkit includes outdated drivers and samples for several adapter cards. Do not use them. They have been replaced:
For the PCI-AC51, use PC-PAMUX-SDK
For the PCI-AC5, PCIe-AC5, G4AC5, and AC5, use PC-DIRECT-SDK

PamScan for MS-DOS

PamScan for MS-DOS is a software utility for troubleshooting Pamux hardware.

Before you download, read the Legal Agreement.

No videos or demos are available for this product.