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- OSMKCM06 - PRINTER DEVICES ATTACHED TO A SERIAL PORT
- 11/01/94
-
- ================================================================
- PRINTER DEVICES ATTACHED TO A SERIAL PORT
- ================================================================
-
- Please Read Entire Document for Full Explanation of Procedures
- ----------------------------------------------------------------
-
- SYMPTOMS:
-
- Serial Printer does not work
- Serial printer seems to get too much data (OVERFLOW)
- Serial printer not printing the entire document
-
-
- RESOLUTION:
-
- Does the printer work under native DOS?
- ---------------------------------------
-
- From real or native DOS, install the printer on the desired COM
- port and try to print to it. Use either the print or copy
- command. Use either DUAL BOOT or boot from a DOS disk.
-
- If the printer fails to print under real DOS, check the cable,
- parallel port, and printer setup.
-
-
- Determining and Setting the Handshaking method.
- ----------------------------------------------------------------
-
- Modern printers are capable of using handshaking signals to
- control the flow of data.
-
- - Software handshaking signals are embedded within the data
- stream that starts and stops the PC when the printer is busy.
- These signals require interpretation by the application and
- are slower than Hardware handshaking.
-
- - Hardware handshaking controls data flow by raising and
- lowering physical signal lines. These signals are called RTS
- CTS DTR and DSR.
-
- The correct handshaking method to use is depends on the printer
- options. Older printers usually use switches located under the
- printers covers. Some new printers have membrane configuration
- panels for setting options. Refer to the printers users manual
- or contact the manufacturer for further detail.
-
- Ususally, setting the printer object for hardware handshaking is
- sufficient. If your printer does not use RTS / CTS handshaking,
- you may try the following combinations.
-
- mode comX RTS=HS, OCTS=ON
-
- mode comX RTS=HS, OCTS=ON, ODSR=ON
-
- mode comX RTS=ON, OCTS=ON, ODSR=ON, IDSR=ON
-
- NOTE: always set MODE comX to = on.
-
-
-
- COMMON PROBLEMS AND SOLUTIONS
- ================================================================
-
- SERIAL PRINTER SEEMS TO GET TOO MUCH DATA (OVERFLOW)
- ----------------------------------------------------------------
-
- Serial Printers use a handshaking protocol. This is either
- software handshaking (XON/XOFF) or hardware handshaking (DSR,
- RTS, CTS). If the printer is configured for SOFTWARE
- HANDSHAKING, use the MODE command to set XON=ON. You may need to
- set all other settings to OFF. If the printer is configured for
- HARDWARE HANDSHAKING, use the MODE command to set RTS=HS, OCTS=ON
- and ODSR=ON. You may also have to set IDSR=ON if the printer
- uses Data Set Ready for Handshaking. If so, you should set ODSR
- to OFF.
-
-
- SERIAL PRINTER NOT PRINTING ENTIRE DOCUMENT
- ----------------------------------------------------------------
- If you are printing very large jobs, you may need to set the port
- for infinite write time out. This is the TO=ON value which is
- set with the MODE COMMAND. This is similar to the ',p' value
- used with the DOS 5.0 MODE command. There may also be a
- handshaking problem.
-
-
- SERIAL PRINTERS AND PLOTTERS
- ----------------------------------------------------------------
- There are very few known problems with using serial printers
- plotters under OS/2 2.x other than having OS/2 driver support.
- The following sections provides detailed information on how
- OS/2 interacts with the printer.
-
-
- SERIAL PRINTER NOT WORKING
- ----------------------------------------------------------------
- Usually a serial printer does not work because the serial
- communication driver (COM.SYS) does not know the handshaking
- method being used.
- Check the product documentation or contact the printer
- manufacturer to determine the type of handshaking the printer
- uses. A serial (RS-232) line tester is also useful.
-
-
- NOTE: If you are printing very large jobs, you may need to set
- the port for infinite write time out. This is the TO=ON value
- which is set with the MODE command. This is similar to the ',p'
- value used with the DOS 5.0 MODE command.
-
- If no data appears to be sent to the printer, set all the
- If it appears that no data is being sent to the priner, set all
- the MODE values to "OFF". If the printer then works,
- individually set the values to "ON" to determine which setting is
- preventing transmission to the printer.
-