Problems with mainframe emulator using EHLLAPI

Brian

16y14.5k.NET

Hi there,
I am using EHLLAPI to connect to a mainframe emulator. I can connect to the session and do some major commands (e.g. connect, disconnect, get cursor, set cursor, sendkey, copy ps to string, etc.). The emulator is Rumba version 5.2. What I can't get my Windows app to do is to chain a bunch of commands together. For example: I want to loop where I use Sendkey, then SetCursor, the Sendkey, SetCursor, Copy PS to String, etc.). I can't get the chain of commands to work, only the first two or so work and then nothing. Thanks in advance.

9 Replies

Know the answer? Post it — somebody with the same question will find it here.

Dennis Durham15y ago
You'e quite welcome, I'm just sorry my reply wasn't timely, (but hope it may provide help in the future). I found the thread while trying to find a better way to use EHLLAPI in VB.NET!
Sam Hobbs15y ago
Thank you, Dennis; I wish I had been able to provide that answer but you know EHLLAPI much better than I do. I heard people talking about it back in the late 1980's but other than that about the only thing I know is that it is an IBM high-level API for communications. I assume it is part of SNA but it pre-dates SAA and I assume that SAA provides a higher-level interface.
Dennis Durham15y ago
Rather than using the System timer, your EHLLAPI most likely has a Wait function, (it's function 4 I believe). The benefit to using the EHLLAPI function is that it watches for the system to become available instead of "waiting" for a specified time, (which may not be sufficient).
Sam Hobbs16y ago
Note that Rumba is not a mainframe emulator; it is a mainframe terminal emulator. I would have understood better quicker what it is that you are doing if you had called it a terminal emulator. Rumba emulates 3270 (and 5250?) style of dumb terminals; I am quite familiar with 3270 terminals, having used real ones for about ten years.
Sam Hobbs16y ago
Okay, so you used Sleep; I was not aware of a function called wait, but I of curse knew about Sleep.

Hopefully that is all you need to do. The thing I don't know is if the amount of time to wait will be consistent; if you don't wait enough time, it won't work and if you use a wait period long enough to work for most or all situations, then you might be waiting longer than needed for most times. I don't know; that is for you to determine.
Brian16y ago
It turns out that I did need to wait a few before using SendKey. I fixed the issue with this:
System.Threading.Thread.Sleep(500);
I put this at the top of my SendKey method. Resolved. Thanks.
Sam Hobbs16y ago
The problem is likely unique to Rumba and automating it from another application; it seems unlikely there will be anyone else with experience with that combination.

I don't know what Wait function you are looking at. My guess is that you will need to process the Rumba window to determine when something has completed. There might not be a simple solution.
Brian16y ago
Sam,

I used this example almost verbatim: http://www.codeproject.com/KB/cs/all_ehllapi.aspx

The only difference is the .dll that Rumba uses. In that sample code there are a few major functions. I am able to use them successfully. But here is what I want to do when I say "chain commands": When a user clicks on one of the buttons on my Windows form I want to call several commands in a row in that click event. For example, I want to do the following: Set the cursor, send in a string, set the cursor, send in another string, etc.

I figured out using some other sample code that the emulator is "busy" when I'm trying to perform functions back-to-back. I don't know if the Wait function is my answer or not. I am still looking into that.

I'm not going to be able to purchase third party software for this solution - the budget doesn't allow for it.

If anyone has seen this kind of thing and has any pointers then I'd be happy to hear them. Thanks.
Sam Hobbs16y ago
It sounds to me as if the problems are not related to EHLLAPI at all; you seem to be atempting to control another application. I think I have heard of Rumba; I have never used it but if I have heard about it, it has existed for about a quarter of a century. The best solution is to use software that allows you to interface with the mainframe more directly. IBM and third-party developers definitely has other software. Controlling other applications using Sendkey and related functions is not as easy as you would like. I think there is not enough information here for people to help you; you need to provide more information, and if you don't have more information, you neeed to spend some more time analyzing the problem. Please provide more details about "can't get the chain of commands to work".