OPTO 22 AC32
  Dual RS-422/485 Adapter
@6C68.ADF - AC32 Dual RS-422/485 Adapter

OPTO22 AC32 Option  ver 2.02 ADFs for AC32, AC33, AC34, 
      LCTRM137.EXE [LCTERM] dumb terminal program (plus other programs)
      OS120.EXE [OPTOSCAN] finds all OPTOMUX stations

195.2  AC34 Single Channel, Isolated RS-485 Serial Port User's Manual

LCTERM Version 1.35 -  Simple terminal program that communicates with LC4 and LC2.

os.exe   OptoScan R.131 DOS
oswin.zip OptoScan Windows 16-bit
oswin32.zip OptoScan Windows 32-bit

The AC32 and AC34 -DO- support the PB16HQ Quad I/O modules.

AC32 Dual RS-422/485 Adapter For Micro Channel Computers  

The AC32 is a dual RS-422/485 adapter card (transient protected) and features two independent asynchronous channels (each able to drive up to 100 devices on a multidrop network). Channel A can be selected for COM1 through COM8 and channel B can be selected for COM2 through COM8. The AC32 offers full hardware and software compatibility with IBM PS/2 Models 50, 60, 70, 80, and compatible computers. The AC32 operates as a full duplex device with transmission speeds up to 38,400 baud for distances up to 5,000 feet using two twisted pairs per channel and a ground.

J1 (A) - DB9
J2 (B) - DB9

AC32 Bank A and B Jumper Settings  

AC32 Bank A and B Jumper Settings  




Pull up jumper for transmit line


Terminate jumper for transmit line


Pull down jumper for transmit line


Terminate jumper for receive line


Pull down jumper for receive line


Pull up jumper for receive line


Enables RS-422/485 driver from RTS output on UART


Not used

AC32 Serial Port Pinout 

Connecting Wire
    This is the wiring between the D shell connector and the first OPTOMUX on the link.

Please note that the pin numbers are labeled on the connector.

Communicating With OPTOMUX

Before applying power to OPTOMUX Brain Board(s), set the baud rate and command protocol on the OPTOMUX Brain Board(s).  The baud rate and command protocol are selected by the B group of jumpers on the OPTOMUX Brain Board(s). (Please refer to the OPTOMUX B1 and B2 Digital and Analog Brain Boards Operations Manual, Form 203 for additional information.)

For the checkout, remove all of the group B jumpers from one OPTOMUX Brain Board and disconnect all other OPTOMUX Brain Boards on the network. This will select a baud rate of 300, the four-pass protocol, and an OPTOMUX address of 255.

 Connect the D shell connector to the AC34 card and turn on the power to the IBM PS/2 and the OPTOMUX.  To test the link, enter the IBM BASIC interpreter and type in the following program. The underlined part of line ten must be changed to COM1 when using the AC34 card as communications port one.

10        OPEN "COM2:300,N,8,1,RS,CS,CD,DS" AS #1
20        PRINT #1,°>FFACD"
30        INPUT #1,B$
40        PRINT B$

When running the program, both the receive and transmit LED's on the OPTOMUX will flash. The IBM PS/2 will display the AFFACD on the screen. If nothing is displayed, verify that all the wiring has been done correctly.