Application Notes: VMS Async Port Configuration

APP NOTES: VMS Async Port Configuration

Port configuration in VMS can be very complex, and most configuration is handled by VMS itself, outside of the Digi driver. The following are typical examples of standard configurations. For further assistance it may be necessary to consult the VMS documentation.

Basic Commands for configuring ports:

SHOW TERM TXA0: <-- shows current port settings
SET TERM TXA0: <-- modifies current port settings
MCR DIGI$DRIVER:DIGITERM SHOW TXA0: <-- shows Digi specific settings
MCR DIGI$DRIVER:DIGITERM SET TXA0: <-- sets Digi specific settings

  To make commands automatic with every reboot, put them in the startup file:
 
SYS$STARTUP:SYSTARTUP_VMS.com



Configuring Terminals:

The default port configuration is correct for most terminals. If a terminal is connected to a Serial Port, then the port will activate on receipt of character, and spawn a login prompt.

Typical changes that need to be made are port speed -- default is 9600 this can be changed with:

SET TERM /PERM/SPEED=38400 TXA0

To get speeds above 115200:

MCR DIGI$DRIVERLDIGITERM SET /PERM/FASTBAUD TXA0:
(turns on fastbaud function)

Parity settings are 81N by default. To change to 71E:

SET TERM /PERM/NOEIGHT_BIT/PARITY=EVEN TXA0

To manipulate hardware and software flow control:

MCR DIGI$DRIVER:DIGITERM SET /PERM/CTSFLOW/RTSFLOW TXA4:
(turns on rtsflow and ctsflow)
 
MCR DIGI$DRIVER:DIGITERM SET /PERM/NOCTSFLOW/NORTSFLOW TXA4:
(turn off rtsflow and ctsflow)
 
MCR DIGI$DRIVER:DIGITERM SET /PERM/NOTTYSYNC/NOHOSTSYNC TXA4:
(turn off ixon ixoff)
 
MCR DIGI$DRIVER:DIGITERM SET /PERM/TTYSYNC/HOSTSYNC TXA4:
(turn on ixon ixoff)

Other settings may be required for particular applications, consult your application and the VMS documentation for guidance on additional steps which may be required.


Configuring Modems:

The following guidance describes the key parameters in simple modem dialin and dialout configuration. Particular applications may require other settings.

SET TERM /PERM/MODEM/DIALUP/HANGUP/SPEED=xxxxxx TXA4
 
  • modem watches dsr and dcd (NOTE: modem precludes use of the altpin flag, as the port will watch both signals), raises dtr and rts when port is opened, and connects/disconnects on DCD/DSR raise/drop
  • dialup identifies the user as a dialup user
  • hangup is disconnect on logout
  • speed=38400, 19200, or whatever the max DTE speed is for the modem


To manipulate hardware and software flow control:

MCR DIGI$DRIVER:DIGITERM SET /PERM/CTSFLOW/RTSFLOW TXA4:
(turn on rtsflow and ctsflow)

MCR DIGI$DRIVER:DIGITERM SET /PERM/NOCTSFLOW/NORTSFLOW TXA4:
(turn off rtsflow and ctsflow)

MCR DIGI$DRIVER:DIGITERM SET /PERM/NOTTYSYNC/NOHOSTSYNC TXA4:
(turn off ixon ixoff)

MCR DIGI$DRIVER:DIGITERM SET /PERM/TTYSYNC/HOSTSYNC TXA4:
(turn on ixon ixoff)

Note: RTSFLOW is available in VMS 7.x only
Note: CTSFLOW may not be used when /MODEM is set


Configuring Printers:

Printers are controlled by Printer Queues. Correct configuration of Queues in VMS requires a thorough understanding of the VMS queue system. The following are only examples. For guidance in configuring other types of queues, consult the VMS documentation, and that in the startup file.

Name the Printer and attach it to the Terminal Device:

DEFINE /SYSTEM PRINTERNAME TXA8


Set up the Terminal Characteristics:

SET TERMINAL PRINTERNAME /PERMANENT /NOBROADCAST /NOTYPEAHEAD /NOWRAP /SPEED=(1200) /WIDTH=(132) /PAGE=(66) /DEVICE_TYPE=VT100

other common device types are UNKNOWN and LA100
(consult the printer documentation for further information on which setting is correct for your printer)

Flow control is set with either:

/HOSTSYNC (for software flow control) or
/CTSFLOW (for hardware flow control)


To queue the printer as the system printer:
 
SET DEVICE /SPOOLED=(SYS$PRINT, SYS$SYSDEVICE:) PRINTERNAME

Consult system documentation to determine if autostart is necessary. If so, make sure resources required by all autostart queues are available, such as disks and printing devices.
 

ENABLE AUTOSTART /QUEUES

If your SYS$PRINT queue is not an autostart queue, then make sure that this command is in your startup file: START /QUEUE SYS$PRINT



These are the initial default settings for a port (though they may be changed through SYSGEN)

$ show term txa0
Terminal: _TXA0:      Device_Type: Unknown       Owner: No Owner

   Input:    9600     LFfill:  0      Width:  80      Parity: None
   Output:   9600     CRfill:  0      Page:   24      

Terminal Characteristics:
   Interactive        Echo               Type_ahead         No Escape
   No Hostsync        TTsync             Lowercase          No Tab
   Wrap               Scope              No Remote          No Eightbit
   Broadcast          No Readsync        No Form            Fulldup
   No Modem           No Local_echo      Autobaud           No Hangup
   No Brdcstmbx       No DMA             No Altypeahd       Set_speed
   No Commsync        Line Editing       Overstrike editing No Fallback
   No Dialup          No Secure server   No Disconnect      No Pasthru
   No Syspassword     No SIXEL Graphics  No Soft Characters No Printer Port
   Numeric Keypad     No ANSI_CRT        No Regis           No Block_mode
   No Advanced_video  No Edit_mode       No DEC_CRT         No DEC_CRT2
   No DEC_CRT3        No DEC_CRT4        No DEC_CRT5        No Ansi_Color
   VMS Style Input
 
$ mcr digi$driver:digiterm show txa0
Terminal: _TXA0:      Device_Type: Unknown       Owner: No Owner               

   Input:        9600    Byte Size: 8   Width:  80    Parity: None
   Output:       9600                   Page:   24    
   Port Speed:   9600

Digital Terminal Characteristics:
   No Hostsync        TTsync             No Eightbit        No Readsync       
   Fulldup            No Modem           No Hangup          Set_speed         
   No Commsync        No Dialup          No Disconnect                        

Digi Terminal Characteristics:
   No Altpin          No Fastbaud        No CTSflow         No RTSflow        
Last updated: Aug 08, 2017

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