Host protocol: TN3270 vs. TN3270E

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1

I have noticed that switching between these two protocols makes a difference to Applinx and would like to verify the behavior.

Our mainframe has a (VTAM) screen where a user can input the CICS region they want to use. Then the sign on screen is provided. After the user submits his/her credentials, another screen passes by very quickly with a result message of the authentication. On success the user receives the CICS prompt while on failure the sign on screen is displayed again.

The result message screen is troublesome to capture. When using TN3270E as the host protocol, Applinx seems to never recognize the fact that the result message screen went by. Using TN3270, Applinx appears to be able capture it.

I can use a console session within Applinx and visually see the differences. With TN3270E, the result message screen is never shown while with TN3270 it is displayed.

Using a normal TN3270 client configured to use the TN3270E protocol, the result screen will appear.

We’ve always used TN3270E with our mainframe and I’m tentative about potential side effects within our Applinx application if I change protocols (for example we use specific LUs for terminals for Applinx). I would like to capture the result message screen though.

Thanks.

2

Hi Erik,

I wouldn’t recommend changing protocols. The TN3270E protocol provides extended screen data that may be lost when moving to TN3270 (text color is just one example).

What kind of data appears in that brief screen?
If the Login fails, wouldn’t the reason also appear on the SignOn screen?

Regards,
Ohad

3

The brief screen displays a message from the security software (Top Secret) that describes why a authentication attempt failed or last sign on date/time if it succeeded. The message also displays information about why a password change failed due to policy.

So I need to get Applinx to see this screen (or at least get at the message data) when using TN3270E.

Maybe having the screen pause a bit longer on the mainframe would do. But is there something I can try in Applinx?

Thanks.

4

BTW, I can see the screen data in the trace but Applinx doesn’t identify the screen.

I can’t post a complete trace here but here are the events. #49 is the missing screen data.

…8<…
[47]
Time=17:30:22.823
RecType=HLLFunc
Type=3
Length=7
Return Code=0

[48]
Time=17:30:22.823
RecType=Send
Length=29

[49]
Time=17:30:22.870
RecType=Recv
Length=195

[50]
Time=17:30:22.870
RecType=Screen Information
Sequential Number=9
Cursor Position=2

[51]
Time=17:30:24.887
RecType=Recv
Length=75

[52]
Time=17:30:24.887
RecType=Screen Information
Sequential Number=10
Cursor Position=1

[53]
Time=17:30:24.887
RecType=Comment
Info=Screen identified [/FinalScreen]

[54]
Time=17:30:29.186
RecType=Comment
Info=Screen identified [/FinalScreen]

[55]
Time=17:30:29.186
RecType=Comment
Info=Screen identified [/FinalScreen]

…8<…

5

And how does that look different compared to TN3270 ?

6

Thanks Wolfgang. I should done that in the first place!

Here’s the trace when using TN3270, where screen /MissingScreen is the missing screen and /FinalScreen is the final screen.

I noticed that the length of the content sent or received differed by 5 bytes. Maybe that’s just a difference in the protocols.

…8<…
[53]
Time=11:54:14.102
RecType=HLLFunc
Type=3
Length=7
Return Code=0

[54]
Time=11:54:14.102
RecType=Send
Length=24

[55]
Time=11:54:14.571
RecType=Recv
Length=190

[56]
Time=11:54:14.571
RecType=Screen Information
Sequential Number=8
Cursor Position=2

[57]
Time=11:54:14.571
RecType=Comment
Info=Screen identified [/MissingScreen]

[58]
Time=11:54:15.415
RecType=Comment
Info=Screen identified [/MissingScreen]

[59]
Time=11:54:16.712
RecType=Recv
Length=70

[60]
Time=11:54:16.712
RecType=Screen Information
Sequential Number=9
Cursor Position=1

[61]
Time=11:54:18.649
RecType=Comment
Info=Screen identified [/FinalScreen]

7

I have some more information to add.

Today the test region on our mainframe was particularly slow in response due to the production region running month-end jobs. This allowed me to test TN3270E again with the idea that the slower response time may allow Applinx to identify the missing screen. Indeed, Applinx was now able to do it.

…8<…
[48]
Time=14:23:17.573
RecType=HLLFunc
Type=3
Length=7
Return Code=0

[49]
Time=14:23:17.573
RecType=Send
Length=28

[50]
Time=14:24:17.635
RecType=Comment
Info=Screen identified [/InitialScreen]

[51]
Time=14:24:17.635
RecType=Comment
Info=Screen identified [/InitialScreen]

[52]
Time=14:24:17.791
RecType=Comment
Info=Screen identified [/InitialScreen]

[53]
Time=14:24:17.853
RecType=Comment
Info=Screen identified [/InitialScreen]

[54]
Time=14:24:17.916
RecType=Comment
Info=Screen identified [/InitialScreen]

[55]
Time=14:24:17.994
RecType=Comment
Info=Screen identified [/InitialScreen]

[56]
Time=14:24:18.057
RecType=Comment
Info=Screen identified [/InitialScreen]

[57]
Time=14:24:18.119
RecType=Comment
Info=Screen identified [/InitialScreen]

[58]
Time=14:24:18.197
RecType=Comment
Info=Screen identified [/InitialScreen]

[59]
Time=14:24:18.260
RecType=Comment
Info=Screen identified [/InitialScreen]

[60]
Time=14:24:18.322
RecType=Comment
Info=Screen identified [/InitialScreen]

[61]
Time=14:24:18.400
RecType=Comment
Info=Screen identified [/InitialScreen]

[62]
Time=14:24:18.463
RecType=Comment
Info=Screen identified [/InitialScreen]

[63]
Time=14:24:18.541
RecType=Comment
Info=Screen identified [/InitialScreen]

[64]
Time=14:24:18.635
RecType=Comment
Info=Screen identified [/InitialScreen]

[65]
Time=14:24:18.744
RecType=Comment
Info=Screen identified [/InitialScreen]

[66]
Time=14:24:18.838
RecType=Comment
Info=Screen identified [/InitialScreen]

[67]
Time=14:24:18.932
RecType=Comment
Info=Screen identified [/InitialScreen]

[68]
Time=14:24:19.025
RecType=Comment
Info=Screen identified [/InitialScreen]

[69]
Time=14:24:19.135
RecType=Comment
Info=Screen identified [/InitialScreen]

[70]
Time=14:24:19.197
RecType=Comment
Info=Screen identified [/InitialScreen]

[71]
Time=14:24:19.275
RecType=Comment
Info=Screen identified [/InitialScreen]

[72]
Time=14:24:19.338
RecType=Comment
Info=Screen identified [/InitialScreen]

[73]
Time=14:24:19.400
RecType=Comment
Info=Screen identified [/InitialScreen]

[74]
Time=14:24:19.478
RecType=Comment
Info=Screen identified [/InitialScreen]

[75]
Time=14:24:19.541
RecType=Comment
Info=Screen identified [/InitialScreen]

[76]
Time=14:24:19.619
RecType=Comment
Info=Screen identified [/InitialScreen]

[77]
Time=14:24:19.682
RecType=Comment
Info=Screen identified [/InitialScreen]

[78]
Time=14:24:19.744
RecType=Comment
Info=Screen identified [/InitialScreen]

[79]
Time=14:24:19.822
RecType=Comment
Info=Screen identified [/InitialScreen]

[80]
Time=14:24:19.885
RecType=Comment
Info=Screen identified [/InitialScreen]

[81]
Time=14:24:19.947
RecType=Comment
Info=Screen identified [/InitialScreen]

[82]
Time=14:24:38.134
RecType=Recv
Length=195

[83]
Time=14:24:38.134
RecType=Screen Information
Sequential Number=9
Cursor Position=2

[84]
Time=14:24:38.134
RecType=Comment
Info=Screen identified [/MissingScreen]

[85]
Time=14:24:38.134
RecType=Comment
Info=Screen identified [/MissingScreen]

[86]
Time=14:24:38.291
RecType=Comment
Info=Screen identified [/MissingScreen]

[87]
Time=14:24:38.353
RecType=Comment
Info=Screen identified [/MissingScreen]

[88]
Time=14:24:38.416
RecType=Comment
Info=Screen identified [/MissingScreen]

[89]
Time=14:24:38.494
RecType=Comment
Info=Screen identified [/MissingScreen]

[90]
Time=14:24:38.556
RecType=Comment
Info=Screen identified [/MissingScreen]

[91]
Time=14:24:38.619
RecType=Comment
Info=Screen identified [/MissingScreen]

[92]
Time=14:24:38.697
RecType=Comment
Info=Screen identified [/MissingScreen]

[93]
Time=14:24:38.759
RecType=Comment
Info=Screen identified [/MissingScreen]

[94]
Time=14:24:38.822
RecType=Comment
Info=Screen identified [/MissingScreen]

[95]
Time=14:24:38.900
RecType=Comment
Info=Screen identified [/MissingScreen]

[96]
Time=14:24:38.978
RecType=Comment
Info=Screen identified [/MissingScreen]

[97]
Time=14:25:17.040
RecType=Recv
Length=75

[98]
Time=14:25:17.040
RecType=Screen Information
Sequential Number=10
Cursor Position=1

[99]
Time=14:25:17.040
RecType=Comment
Info=Screen identified [/FinalScreen]

8

Hi Erik,

When you’re running this host application from another emulation software (such as P-com for example) , do you always see that screen?and for how long?

I suggest you open a support request, with all the data you provided here. This would give our guys a nice head start on this issue.
If possible, please add the trace files to the request.

Ohad

9

When using TN3270 Plus emulation client under normal system load, the screen is present for about 1 second.

10

Hi Erik,

It sounds like a bug.
You should continue this through global support.
If you haven’t already done so, open a support request and attach the relevant information to it (such as GCT files).

Best regards,
Ohad