Configuring a Device Group for an OSDI

At the application level DP4 uses the same device architecture and APIs for communicating with both "ordinary" printers and specialised multi-component devices such as Retail or Financial POS equipment controlled via an OSDI. As a result setting up a printer may seem a rather complicated business. Conversely, when setting up a Device Group for an OSDI some of the printer facilities may be irrelevant.

The following is a guide to defining a Device Group in DFSETUP. On this page we will use a device group for the "DP4 Till" (a device using an OSDI) as an example. For an example of configuring a Device Group for a printer OSDI click here.

1. From the System Setup (DFSETUP) main menu, select Printer and device set up..., then select Device group (DG) description. This choice will allow you to define a Device Group

2. Enter the name you wish to give to your Device Group (in this case DDI_TILL). You will be prompted to add your new Device Group to the system. After adding it the Device Group Editing Menu is opened.

3. (Optional) Select Copy and select one of the existing devices if you think that your device is similar to one of the devices already on the system database. This will copy all the information for the selected device group. (A bug in DFSETUP means that the screen display is not correctly updated to show the copied properties, in releases of DP4 prior to 4.620.)

4. Select Device group description from the Device Group editing menu. This will place you in the screen below (the screen shown is for OS/2 or MS-DOS):

   

5. Enter the description of your Device Group. The next part of the dialog is slightly different depending on whether you are using release 4.621 or an earlier release of DP4:

   • If you are using release 4.620 or earlier then you can accept all the default values until you are prompted for Special device. Set Special device to Yes (or check the checkbox). This tells DP4 that your Device Group uses an OSDI.

   • If you are using release 4.621 or later then accept all the default values until you are prompted for the Device Family. Select OSDI controlled device. This tells DP4 that your Device Group uses an OSDI. You can accept the default values for Soft form feed and Null character

6. Set Hidden device to Yes to prevent the DP4 Till appearing as an available option for general purpose printing.

7. Select printer port NUL, or, if you are running on Unix and Linux, prn7. The combination of special device and this port (the actual port is the same in both cases) signifies to the DP4 Terminal Manager that an OSDI is required. For some operating systems the output is actually redirected to NUL (for example MS-DOS), for others NUL is not used. For example under OS/2 the OSDI is a Dynamic Link Library and the NUL port is not used.

   Note that the other printer ports listed are for regular printers. Even if your OSDI uses one of these ports for communication with the device you must specify the NUL port or prn7.