line printer printing at 4800bps with frequent pauses and at 9600 or high hang up

[kumarasamy]

we have a genicom line printer that was connected through print server X-Connect-II with Micro VAX3100/Open VMS 6.3.Now X connector becomes faulty.I tried with serial port from Terminal server and LAT support.
Printer started working first few pages at 9600 and higher speed and stopped with scrren error message " data set hang up".
when I changed the speed to 4800, it works with out error and pauses frequently.it starts printing itself witout our intervention,
I tried with "set device/spooled=(que name,device:)command defined in the que but no improvement and used another command "set term lta501:/permanent /dma" but no change .

advice is requested

[Volker Halle · Accepted solution]

kumarasamy,

flow control happens solely between the terminal server port and the printer itself. You should test, whether flow control works correctly by using the

Local> TEST PORT n

command on the Terminal Server (see HELP TEST PORT for more options). You will have to find out, what type of flow control the printer is using and set the characteristics of the terminal server port accordingly. You can use the command Local> SHOW PORT n STATUS to see the status of the serial line.

The data set hangup error might indicate, that the printer is using hardware flow control and the terminal server port is set to software flow control.

Volker.

[kumarasamy]

Hai Mr.Volker

Thanks for your advise

I tested with command ,
Local>test port 3
It worked fine because it took hardly any time to print and then
I increased the count to 100
.ie,
Local> test port 3 count 100
it printed with a pause

Printer is configured for serial port RS 232 with Xon/Xoff ready/Busy enabled, robust xon enabled.

at terminal server port 3

Local>show port 3 status

Access remote
Status idle
Session 0
Input xoffed No
Output xoffed No
Output control DTR
Input signals DSR RXD

Current service:
Current node :
Current port :

All above three are blank.


Printer has menu by which I can alter the options.
speed at both ends is set to 4800

kumarasamy

[Robert Gezelter]

kumarasamy,

From your description, it sounds like the printer has BOTH hardware and software flow control enabled. This could cause a problem. Pick one of the two (I generally pick software flow control), and set both the terminal server and printer to use that technique. If you choose software flow control, DISABLE hardware flow control on both sides.

If flow control is incorrectly configured, many different strange things can occur (e.g., characters incorrect, paper spewing wildly).

- Bob Gezelter, http://www.rlgsc.com

[Volker Halle]

kumarasamy,

how long is the pause ? During the pause, can you look at Local> SHOW PORT 3 STATUS from another terminal connected to the DECserver or connected to the DECserver console via MOP ? What are the Xon/Xoff and Input/Output signal settings during the pause ?

I found the following description of the 'robust XON' feature:

Robust Xon
This parameter behaves the same as a normal Xon/Xoff protocol, except that
with this parameter enabled, the Xon code will be sent every 5 seconds when the
printer is ready to accept data. OFF is the default.

Volker.

[kumarasamy]

hai volker.

Pause is very much noticeable like a new job is assigned to printer when it is idle.
printing stops completly then it starts again. it is about a minute or less.
Then I changed the speed to 9600 at 3 places , printer, lat$systartup.com file and port 3 of T server.
there is some improved changes found over privios status that "data set hang up" .
I printed about 50 pages. it is through with pause.
while printing I noted staus of port 3 as you said.
port no:3 server: lat......
Access :remote current service:node name
status :connected current node :lat port
sessions :1
input xoffed - no
output xoffed - no
output signals :DTR
Input signals : DSR RXD

I think Robust XOn only creats differences.

I will chnage the speed to 19200 at all the three places and get back to you with the result
thanks

[Volker Halle]

kumarasamy,

you only need to set the speed at the terminal server port and the printer. The serial line communication protocol only happens between the terminal server port and the printer serial interface.

The communication between the VMS system and the terminal server uses the LAT protocol, which has it's own flow control.

To get the LATSYM symbiont out of the picture, you could set the LTA device to /NOSPOOL, STOP/QUE/RESET the print queue and do a plain $ COPY print-file LTAx:

Volker.

[kumarasamy]

Mr. volker

I need to change the speed at 3 places . if not , printer gives FRAMING ERROR as well as printing with out stopping. we need to switch off and on printer to return to normal.

any way , I increased speed to 19200 at lat$ file, printer and Tserver port .
with robust xon printer works normal. that delay disappeared and Data set hang up never did not come so far.
let us hope the problem solved.
Thanks for your advise.

[Volker Halle]

kumarasamy,

if REMOTE MODIFICATION is enabled on the terminal server port, you can change/set the speed via the LAT protocol from the host.

You could disable this feature with:

Local> DEFINE PORT x REMOTE MODIFICATION DISABLE

Volker.

[kumarasamy]

volker

I encountered the error message "Data set Hangup".
printer displayed paper out message when there was no paper in the printer. then I put another paper box for feeding. it took about three minutes by the time printer que gave error message.
after wards the printer did not take data.
then I had to delet the stopped one and gave another print job with same file with /pages=(,) qualifier.

even for papaer changing time printer does not hold and send error to system

how to avoid this?

[Volker Halle]

kumasaramy,

there is no mechanism in the OpenVMS LATSYM print symbiont to read any 'messages' from the printer.

The only communication mechanism between printer and terminal server port is flow control (either HW or xon/xoff). If the printer is configured to drop DTR when it's offline or out of paper and the terminal server port is configured to watch DTR/DSR, an existing LAT session will be terminated (data set hangup) and the LATSYM print queue will be stopped, if the printer drops DTR.

Maybe you can configure your printer to send XOFF, if it is running out of paper. Then the LAT session would continue to exist, but the queue wil enter the 'stalled' state.

Alternatively, you could configure the printer to do hardware flow control (by toggling DTR) and also configure the terminal server port to do hardware flow control. Then a paper-out, printer powered off or printer buffer full will cause the terminal server to stop sending data.

Volker.

[kumarasamy]

with trial and error setup was changed to get smooth printing without pausing.
I achieved good speed by changing xoff/on in both end but I have to resend new job that is distured by any reason for changing paper or settin page on form. because once the printer is disturbed while printing, it just initialied.
anyway we ordered for print server "XConnectII 8 s" for restoration.
thanks