Overview

The MODEL 109A is an interface converter that allows Centronics and RS-232 devices to communicate with each other (a computer with an RS-232 output to a Centronics printer, for example).

The unit is bi-directional enabling you to convert from serial to parallel to serial. It is configured with 512 KB of memory allowing it to serve as a printer buffer.

These two way converters provide a DB-25 RS-232C (DCE) compatible connector, and a C-36 Centronics connector. The serial baud rate is from 1200 to 115200 bps. (selectable by DIP Switch). The parallel interface speed for the (buffered) Model 109A is 1.5 MB/sec.

The units support both hardware and software (XON/XOFF) handshaking. Setup is extremely easy. All that is involved is setting the DIP Switch and connecting the cables.

Features

• DIP Switch Sets Data Direction
  
  
• Built in Buffer for Efficient Operation
  
  
• Both Hardware and XON/XOFF Handshaking
  
  
• Easy Installation
  
  
• Compact Size
  
  

Installation

Switch Configuration Overview

The Model 109A is configured by setting an eight segment DIP Switch as follows:
 

An explanation of each DIP Switch setting is given below:

Note:
1. When the segment is set in the direction of the arrow, it is ON.
2. In each table, the default setting is highlighted

Setting DIP Switches
Baud Rate:

The baud rate is set with DIP Switch segments 1-3, as shown in the table below

Handshake:

Data and Stop Bits:

Parity:

 Conversion Direction:

Cabling
Serial to Parallel:

When performing a Serial to Parallel interface conversion:

1. Plug the female end of a 25/9-pin to 25/9-pin male/female serial cable into the PC's serial port.

2. Plug the male end of the 25-pin to 25-pin male/female serial cable into the Model 109A's serial connector.

3. Plug the female end of a C-36 to C-36 male/female printer cable into the MODEL 109A's printer connector.

4. Plug the male end of the C-36 to C-36 male/female printer cable into the printer.
Note: If your serial cable is long enough, you can plug the MODEL 109A directly into the printer without the need for a printer cable.

5. Plug the Power Adapter into an AC source; plug the Power Adapter cable into the Model 109A's power jack.

Parallel to Serial

When performing a Parallel to Serial interface conversion:

1. Plug the male end of a 25-pin (male) to C-36 (female) printer cable into the PC's parallel port.

2. Plug the female end of the 25-pin to C-36 male/female printer cable into the Model 109A's Centronics connector.

3. Plug the male end of a 25-pin to 25-pin male/female serial cable into the MODEL 109A's serial cable.

4. Plug the female end of the 25-pin to 25-pin male/female serial cable into the printer's serial port.

5. Plug the Power Adapter into an AC source; plug the Power Adapter cable into the MODEL 109A's power jack.

Serial Port Cabling

Parallel Port Cabling

Operation

When operating the MODEL 109A, please take note of the following:

1. Since the MODEL 109A is a DCE device, the serial device it connects to must be configured as a DTE device.

2. In DCE mode, the unit uses RTS/DTR (pins 5 and 6) handshaking. When RTS/DTR is at +9V, the computer is allowed to transmit data. When the unit is busy, it sets the RTS/DTR link to -9V, and the computer stops transmitting data. Consequently, if the computer can not identify the RTS/DTR signal, it may result in data loss.

3. The unit is powered by the host RS-232C interface. In addition to the TxD line, it is recommended that the host RS-232C interface (MC 1488, SN 75188, or equivalent IC's), also support RTS and DTR lines, which provide a power source above ±9V, to ensure normal operation of the unit.

4. The unit's baud rate, data length, stop bits and parity settings must be configured to match those of the computer.

5. You must reset the parallel printer before printing.

Appendix
Troubleshooting

If the above solutions fail to alleviate the problem, contact your dealer for help.

RS-232C Interface Specification

The RS-232C Interface DCE mode (default) specifications is given in the table below:

Centronics Interface Specifications
The Centronics Interface Specification is given in the table below:

Specifications:

Radio & TV Interference

Warning. This equipment generates, uses and radiates radio frequency energy and if not installed and used in accordance with the instruction manual may cause interference to radio and television reception. It has been tested and found to comply with the limits for a Class A computing device in accordance with the specifications in Subpart J of Part 15 of the FCC Rules, which are designed to provide reasonable protection against such interference when operated in a commercial environment. Operation of this equipment in a residential area is likely to cause interference, in which case the user at his own expense will be required to take whatever measures may be required to correct the interference.

If this equipment does cause interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures.

1. Reorient the receiving antenna.

2. Relocate the computer with respect to the receiver.

3. Move the computer away from the receiver.

4. Plug the computer into a different outlet so that the computer and receiver are on different branch circuits.

5. Ensure that the mounting screws, attachment connector screws and ground wire are tightly secured.

6. Ensure that good quality shielded and grounded cables are used for data communications.

If necessary, the user should consult the dealer or an experienced radio/television technician for additional suggestions.

Limited Warranty

IN NO EVENT SHALL THE DIRECT VENDOR'S LIABILITY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES RESULTING FROM THE USE OF THE PRODUCT, DISK, OR ITS DOCUMENTATION EXCEED THE PRICE PAID FOR THE PRODUCT.

The direct vendor makes no warranty or representation, expressed, implied, or statutory with respect to the contents or use of this documentation, and especially disclaims its quality, performance, merchantability, or fitness for any particular purpose. direct vendor also reserves the right to revise or update the device or documentation with the hout obligation to notify any individual or entity of such revisions, or update. For further inquiries, please contact your direct vendor.

Document No. 0315-0324/rev -

Model	Product Info
109A