It's a common scenario. Your MIS department supports DOS and Windows client desktops. You've finally got the 5250 emulation and PC Support problems solved on these platforms. Everyone has 5250 sessions to the AS/400. New users are set up painlessly, and things are running smoothly.

Enter a renegade faction. A certain group of users has installed OS/2 on their desktops, without following MIS procedures and standards. They need connectivity to the AS/400 pronto, and guess who gets to do the honors?

Reality Bites

If OS/2 is in your future or if the above scenario rings a bell, you may be faced with using Communications Manager/2 (CM/2) for OS/2 to provide 5250 emulation to your AS/400s or S/36s. There is an alternative to CM/2 for the AS/400: Communications Manager/400 (CM/400). You can purchase CM/400 separately for around $100. However, beginning with V3R0M5, IBM bundles CM/400 as part of Client Access for OS/2. Configuration of CM/400 has a lot in common with CM/2 configuration for the AS/400, so much of what you learn here can be applied to the CM/400 product. CM/400 does not include a 5250 emulation feature as CM/2 does. But, beginning with V3R0M5, the RUMBA/400 5250 emulation product is included with Client Access for OS/2. RUMBA/400 5250 emulation configuration is considerably different than CM/2's 5250 emulation. The similarities and differences between using CM/400 and RUMBA/400 versus CM/2 and its 5250 emulation is material for another article. Here, the focus is on 5250 emulation through CM/2.

If you've faced the daunting task of setting up 5250 emulation in an OS/2 environment, you already know it can be intimidating. If you haven't yet had the opportunity, perhaps this article will help you navigate the myriad of screens and decisions that CM/2 holds in store for you. However, before I get into the nuts and bolts of installing 5250 emulation, I'd like to describe the OS/2 environment and some of the pertinent features of CM/2.

How About OS/2?

OS/2 is a nice product for those who like a multitasking graphical environment. It is a software developer's dream come true and an end user's answer to complex task-switching. I utilize OS/2 on all my hardware-home and work, laptop and desktop. I develop OS/2 and DOS applications; on a typical day, it would be common to see two OS/2 windows, two DOS windows, a couple of Windows sessions, a 3270 session, and two or more 5250 sessions on my desktop. Although this arrangement might sound a bit crowded, there's no turning back once you get hooked on it.

CM/2 Overview

Enough OS/2 evangelizing. OS/2 gets the job done, and you'll probably have to deal with it sooner or later. CM/2 is a vehicle that can provide 5250 emulation support for OS/2. CM/2 has a wealth of additional capabilities that might offer solutions to your communication needs.

CM/2 is the core of all communications functions that take place in an OS/2 environment. It includes support for networking, System Network Architecture (SNA), asynchronous communications, terminal emulation, and various configuration services. The focus of this article, 5250 emulation, is just a small part of CM/2.

Let's look at the 5250 side of CM/2. CM/2 provides interactive access to the AS/400 and S/36 in a single-byte character string (SBCS) environment or to the AS/400 in a double-byte character string (DBCS) environment. Access to the S/36 is enabled through Synchronous Data Link Control (SDLC) and token-ring direct connections. In SBCS and DBCS environments, the direct connection to the AS/400 is provided through Ethernet (ETHERAND), twinaxial, X.25, SDLC, token-ring, ISDN Data Link Control (IDLC) using ISDN, and X.25 using ISDN. Other connections are available by routing through network nodes or bridges.

CM/2 emulates a variety of workstations and printers. Consult your CM/2 user's guide if you need more information on supported peripherals.

How High Can You Go?

CM/2 supports a maximum of 26 sessions, 15 of which can be 5250 sessions. The 26-session maximum can include a combination of terminal and printer sessions. The session limit may be reduced, depending on the version of OS/2 you are using and other application resources on your OS/2 platform. For example, if you're using OS/2 2.0 or lower, there is a limit of 16 windows that can be simultaneously displayed.

The 5250 emulation sessions can be configured to any number of AS/400 host systems. You may find it easiest to set them up to a single host and use display station pass-through to access other systems. This lets you use the quick-configure options of CM/2. If you want to connect directly to multiple AS/400s, you must describe additional links, which takes you down in the bowels of advanced CM/2 configuration. I'm no glutton for punishment; I like to keep things as simple as possible.

What Else Can CM/2 5250 Do?

Each emulation session allows additional configuration by utilizing the system pulldown menu. The menu gives you access to a variety of CM/2 functions including keyboard remapping, color and font customizing, mouse hot spots, alarms, printing, and clipboard cut, copy, and paste functions.

The emulator high-level language application program interface (EHLLAPI) provides an interface to 5250 emulation. EHLLAPI gives client application programs a way to obtain information by accessing the workstation's video buffer. The characters displayed on the screen are imported directly into the client program. This process is often used when giving AS/400 legacy applications a graphical user interface (GUI).

This technique, referred to as screen scraping, provides an interface from the client application program to workstation objects such as keyboards, sessions, screens, presentation spaces (the entire physical screen area occupied by an emulation session), the cursor, and the operator information area (OIA) of a host session. The OIA is the area at the bottom of the presentation space that displays row, column, keyboard inhibited, and other operator status information.

User Profile Management (UPM), another function of CM/2, provides the management of group and user facilities. UPM lets you set up user IDs and passwords; then, once you log into UPM for each session, your ID and password are automatically sent to the 5250 emulator and on to the host system for verification.

5250 emulation printer sessions are managed from the Emulator Print Control window. This is a single session that lists and controls all configured printers.

The PC Organizer provides AS/400 emulation sessions with a text editor and is used to start a PC command from an AS/400 host. It can also be used to support DisplayWrite operations. Once a 5250 session is started, CM/2's PC Organizer function can be used without starting up PC Support's PC Organizer function. PC Support and CM/2 do not share PC Organizer configurations so you won't run into any conflicts.

Installation Overview

I'm going to assume you already have CM/2 installed and that you want to utilize the quick configuration option of CM/2. Installing CM/2 and Advanced 5250 Emulation Configuration is beyond the scope of this article. At the end of the article, though, I will discuss some of the advanced configuration options and show why and when you would need to consider them.

I strongly recommend that you read the 5250 emulation part of Chapter 1 and all of Chapter 8 in the IBM Communications Manager/2 Workstation Installation and Configuration Guide. The manual offers a good overview of the installation process and describes the differences between quick and advanced configuration.

If your connection type is a token-ring, Ethernet (ETHERAND), or other local area network (LAN), a PC network, SDLC (non-ISDN), or twinaxial, then Quick Configuration works; otherwise, you need to use advanced configuration. By default, on the initial definition of a configuration, CM/2 uses the quick configuration mode. If you change a value through the advanced configuration method, the quick configuration method may no longer be available.

The Workstation Installation and Configuration Guide outlines the quick configuration parameters and provides a worksheet to record your choices. It shows you the parameters that relate to the connection type you will use. The parameters that need to be gathered for Ethernet and PC network connections are the same as for token-ring.

Time to Install

You've finally come to the fun part! Open up the CM/2 folder by double-clicking on the Communications Manager/2 icon. In this folder, double-click on the Communications Manager Setup icon. When the Communications Manager Setup dialog box appears, select the Setup button to obtain the Open Configuration dialog box. This dialog box allows you to select a configuration file or create a new one. To create a configuration file, key a name for the configuration file in the Configuration text box and a brief description in the Description text box. If configuration files exist, they will be listed in the Configurations list box.

If you select an existing configuration, before you continue, you should make a backup of the configuration file. To do this, start up a new OS/2 session (or go into an existing one) and change to the CMLIB directory on the drive where CM/2 is installed (more than likely, the directory you want is C:CMLIB). You should find a file name that matches the configuration definition name with an extension of .CFG. You may also find additional files with the same name but different extensions. Make a copy of all the files with the same name as the configuration definition. Once you have a backup, go back to the Open Configuration dialog box and single-click on the OK button.

The Communications Manager Configuration Definition dialog box appears. It contains two list boxes. The list box on the left allows you to select the workstation connection type. In the example illustrated in 1, Token-Ring or Other LAN Types is already selected. In the list box on the right, choose 5250 emulation and CM/2 displays a diagram of a token-ring network within the dialog box as illustrated in 1.

The Communications Manager Configuration Definition dialog box appears. It contains two list boxes. The list box on the left allows you to select the workstation connection type. In the example illustrated in Figure 1, Token-Ring or Other LAN Types is already selected. In the list box on the right, choose 5250 emulation and CM/2 displays a diagram of a token-ring network within the dialog box as illustrated in Figure 1.

Choose the Configure button and the quick configuration dialog box appears. In this box, titled 5250 Emulation through Token-Ring, you enter all of your parameters. 2 shows the dialog used in my example.

Choose the Configure button and the quick configuration dialog box appears. In this box, titled 5250 Emulation through Token-Ring, you enter all of your parameters. Figure 2 shows the dialog used in my example.

In the Network ID field, enter your network ID. You can obtain the network ID by executing the Display Network Attributes (DSPNETA) command and using the contents of the Local Network ID (LCLNETID) field. This is the name of the network for which your 5250 emulation sessions will be established.

In the field for Local node name, enter the remote location name of your workstation's APPC device. It becomes the control point (CP) name for your node.

The Local node ID field defaults to a value of 05D 00000. You can accept the default value. (In link station negotiations, these eight characters determine which link workstation is primary and which is secondary. The workstation with the higher value becomes the primary link workstation. If the values are equal, both stations generate a random number to determine which is primary.)

In the Partner LU name field, enter the fully qualified partner name of the AS/400's logical unit (LU) that you will establish 5250 emulation sessions with. This full name consists of the network ID (field 1 of the dialog), a period (.), followed by the local control point name of the remote AS/400. (Use the DSPNETA command on the remote AS/400 to determine the local control point name.)

Enter the mode name in the Mode name field. The mode name most often used with PC Support is QPCSUPP. If you are not using PC Support, the mode name is usually #INTER. You supply the name of the mode that controls the 5250 emulator session. Mode names are assigned to sets of commonly grouped transmission characteristics like class of service and session routing.

For this example, select the AS/400 button for the Host type information entry.

For the LAN Destination Address, enter the address of the adapter on your network's communications controller or gateway. To find the address of your AS/400's token-ring adapter, start with the Work with Hardware Resources (WRKHDWRSC) command and specify *CMN in the TYPE parameter. Find the token-ring port in the list and use option 5 (Work with configuration descriptions). A list of configuration descriptions for the token-ring port will appear. Use option 5 (Work with description) for any of the configuration descriptions on the list. The Work with Line Descriptions panel will appear. Use option 5 (Display) on any of the line descriptions on the list. You'll find the Local adapter address near the bottom of the display.

In the Number of Terminal Session field, specify how many 5250 emulation sessions you want to have available. Each one becomes a separate window on your desktop when CM/2 is loaded. In the Number of Printer Sessions field, specify the number of AS/400 printer sessions you want.

Finally, click OK to return to the Communications Manager Configuration Definition dialog. When you click the Close button, CM/2 verifies your configuration. If CM/2 is currently active on your OS/2 machine, you will be asked, "Would you like to dynamically update your SNA resources?" Select Yes to update the currently running SNA resources with the changes you made during the configuration. When this process completes, select Close from the Communications Manager Setup dialog box.

If CM/2 is currently running on your machine, open up the CM/2 folder and double-click the Stop Communications Normally icon. Give CM/2 time to terminate. If CM/2 is not running on your machine, continue on. Double-click the Start Communications icon in the same folder. Assuming that your local node IDs are configured on the AS/400 (or if the AS/400 is set up for auto- configuration), you will have one 5250 emulation session for each one you requested. You will be presented with the Node Logon dialog. Enter your user ID and password, and you should receive the AS/400's sign-on screen in each emulation session.

When Do I Need to Use Advanced Configuration?

In most cases, any changes made after the quick configuration must be made in advanced mode. (Click the Advanced button on the 5250 Emulation Through Token- Ring dialog). In fact, you will probably never see the quick configuration section again, although its parameters are recorded in the advanced section.

For some tasks, including those in the list that follows, you can and in some cases must use the advanced configuration method.

o Changing the long session/LU name. o Changing 5250 session definition default values. o Selecting the mode for a session. o Defining a partner LU alias. o Changing or creating a terminal session keyboard profile. o Changing or creating a terminal session color profile.

If you feel adventurous, you might want to explore advanced configuration. There's no way to cover it all in this article, but you can try it out and read the manual to get an idea of the capability provided.

Some attributes of a 5250 session can be changed while running an emulation session. These include color, keyboard, or printer definitions.

If you want to configure your session attributes, use the menu bar of your session window. Examples of some of the available attribute configurations are shown in 3. If you have questions about these options, refer to Chapter 8 of IBM Communications Manager/2 Workstation Installation and Configuration Guide.

If you want to configure your session attributes, use the menu bar of your session window. Examples of some of the available attribute configurations are shown in Figure 3. If you have questions about these options, refer to Chapter 8 of IBM Communications Manager/2 Workstation Installation and Configuration Guide.

Ok, Give Me the Bad News

CM/2's 5250 emulation has a few minor inconveniences. CM/2 does not support file transfer within 5250 emulation, a feature that is provided within CM/2's 3270 emulation. Configuring complex environments (simultaneous sessions with multiple hosts) is a bit overwhelming at first, but this is probably true with any 5250 emulation platform. The IBM Communications Manager/2 Scenarios guide is helpful should the need arise.

It's a Wrap!

You can see that OS/2's CM/2 provides a wide set of capabilities and features. You may not need all of them, but some are sure to come in handy. I hope you agree that it is not all that difficult once you know how to navigate the Communications Manager Setup dialog boxes.

Take some time to enjoy the environment available with the sophisticated, multitasking operating system of OS/2. You should find yourself much more productive than when using other 5250 emulation platforms or products.

Mike Davenport is an associate technical editor for Midrange Computing.

REFERENCES Communications Manager/2 User's Guide (SC31-6108). Communications Manager/2 Workstation Installation and Configuration Guide (SC31-7169). IBM Communications Manager/2 Scenarios (SC31-6174).

Configuring 5250 Emulation with OS/2

Figure 1 Selecting a Connection Type

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 Configuring 5250 Emulation with OS/2
 
 Figure 2 5250 Emulation Quick Configuration
 
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 Configuring 5250 Emulation with OS/2
 
 Figure 3 Session Attribute Configurations
 
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