Printers

Before you can use a printer, you must connect it to your i5 system. Before that, you have to configure the printer. The configuration process can be left to the system if you are using automatic configuration (system value QAUTOCFG set to ‘1’), or you can create the device description yourself.

Creating a device description for a printer involves the use of the Create Device Description (Printer (CRTDEVPRT) command. Many parameters will have to receive values based on what the printer is, or where you are connecting it. Other parameters can be set to different values, depending on how you want to control the printers. This section deals with these management parameters.

Automatic Online (ONLINE)

The ONLINE parameter determines whether the system automatically varies on the printer at IPL time. It defaults to *YES. ONLINE should be left to its default value unless a compelling reason exists to change it to *NO.

If ONLINE(*NO) is specified, the system operator (or the user who normally controls the printer) will have to manually vary on the printer and start its printer writer before users can get any printing done. This action seems like an additional burden with no immediate advantage.

Message Queue (MSGQ)

Printers run into trouble now and then. For example, a printer may be printing reports on standard paper for hours until a user requests purchase orders, which must be printed on special preprinted forms. When the system begins to send the purchase order spool file, the printer realizes that the forms it has installed and the new spool file forms do not match. Or, perhaps your printer's ribbon jams, or someone turns it off by accident, or it runs out of paper.

Any of these situations require operator intervention, and the only way your printer can communicate this fact is by sending a message. The MSGQ parameter names the message queue where this message is sent.

MSGQ defaults to QSYSOPR, but this is a poor choice in many cases. QSYSOPR is a very busy message queue, especially in large installations, because QSYSOPR receives many messages from all kinds of jobs running on the system.

Tip 

You should designate a message queue other than QSYSOPR to receive the printer messages. You can use a single message queue for all your printer devices, or group them together so that some (but not all) printers share a message queue, or you can give each printer a separate message queue.

If you use a single message queue, you will know where to look without having to think. You could give this unique message queue a significant name, such as PRINTERS, and put it in a library where you can always find it using the library list support. Check on printer messages by executing the command:

      DSPMSG MSGQ(PRINTERS) 

The disadvantage of a single message queue is obvious. It is almost as bad as using QSYSOPR itself. PRINTERS will receive messages from all printers, and you will have to be especially careful that you don't confuse one with another.

Grouping printers by message queue is somewhat better. You could create a message queue for the Accounting department and use it for all printers located in that department. The danger of misinterpreting a message is less than if you had a single message queue, but it still exists.

Using a separate message queue for each printer works best, and you can simplify the setup by giving the message queue the same name as the printer device it services. In this way, if printer PURPRT01 (in Purchasing) has stopped printing, you can display messages as follows:

      DSPMSG MSGQ(PURPRT01) 

Printer Error Messages (PRTERRMSG)

Some messages are important and others are not. The PRTERRMSG parameter of CRTDEVPRT determines how the system handles recoverable error situations. If you specify *INQ (the default value), the system sends an inquiry message. Someone must reply to this message before the printer can continue. If you specify *INFO, however, the message is sent but printing continues.