Example of a user-written terminal error program

The DFHTEP recursive retry routine is an example of the logic steps necessary to design a portion of the terminal error program. In Figure 1, 10 retries are provided for each terminal; however, the logic could be used for any number of retries. The following assumptions are made:

USER FIELD A

(PCISAVE)

represents a 6-byte field in the process control information (PCI) area of the TCTTE. This field is used to preserve the count of input and output from the TCTTE when the first error occurs. These counts are contained in 3-byte fields located at TCTTENI and TCTTENO within the TCTTE.

USER FIELD B

(PCICNT)

represents a user-defined field used to accumulate the count of recursive errors. It should be in the process control information (PCI) area of the TCTTE.

SYSTEM COUNT

(TCTTENI)

represents the 6-byte field in the TCTTE that contains the terminal input and output counts (TCTTENI+TCTTENO). In the example, these two adjacent fields are considered as one 6-byte field.

Because this example requires access to the TCT terminal entry (TCTTE) to examine the SYSTEM COUNT and to locate the process control information (PCI) area, the DFHTCTTE symbolic storage definition is included so that fields can be symbolically referenced.