This appendix contains an example LU 6.2 application.
The application in this example enables a clerk in a retail store
to check the credit of a buyer before allowing the buyer to charge
a purchase to a credit card. The retail store has an HP 3000
running LU 6.2 API. The credit information is stored in a VSAM database
on an IBM processor running CICS. The TP on the HP 3000
calls the MCAllocate intrinsic to allocate the conversation, and the
TP on the IBM processor is started up in response to the allocate
request.
The example TP on the HP 3000 is written in COBOL
II and in Pascal. It performs the following tasks:
It calls the TPStarted intrinsic to initialize the TP, and then it calls the
MCAllocate intrinsic to allocate a conversation with the
CICS TP on the IBM processor.
It prompts a terminal user for a social security
number and name, and then it reads the data from the terminal.
It translates the data to EBCDIC and sends it to
the CICS TP on the IBM processor.
It receives a data record from the CICS TP and translates
it to ASCII.
It interprets the information in the data record
and displays "Credit Approved" or "Credit
Denied" on the terminal screen.
It asks the user whether he or she wants to quit.
If the user responds with "Y," it deallocates
the conversation; otherwise, it prompts the user for another social
security number and name.
The example TP on the IBM processor is written in PL/1. It
performs the following tasks:
It receives a social security number
and name sent by the TP on the HP 3000.
Using the social security number as a key, it searches
the VSAM database for credit information on the buyer.
It sends the information from the database to the
TP on the HP 3000, or it reports an error. The remote TP
can return any of 3 error codes:
001 — The SS# is not in the database.
002 — The SS# is in the database, but the name does
not match the name sent by the HP 3000.
003 — Miscellaneous system errors.
It waits for another data record or a deallocate
request from the TP on the HP 3000.
Figure B-1 “Data Set for the Example Program” is a sample credit card verification
report generated from the database on the IBM processor. This is
the data set used by the example application in this appendix.
Figure B-1 “Data Set for the Example Program” is a sample credit card verification
report generated from the database on the IBM processor. When the
CICS TP receives a social security number and name from the TP on
the HP 3000, it sends the data record associated with the
social security number and name.
