DSNA202E DSNACA00 TCB=address CANNOT USE 'OPEN', PRIOR OPEN OR SQL ALREADY CONNECTED APPLICATION TO DB2

Explanation
 An OPEN request was received but a DB2® thread had already been created for the specified
TCB. This is a user error. The message is accompanied by return code
(R15) 200 and code (R0) 00C10202.

System action
 No new DB2 thread
is created and an error return and reason code are issued. The DB2 call attachment facility is
ready for more input.

System programmer response
 Refer the problem to the programmer
using the DB2 call attachment
facility.

Programmer response
 Your application program had already (explicitly
or implicitly) established an OPEN level connection to DB2.  You cannot do this again until the original
OPEN is terminated. 'Explicit' OPENs occur when an application issues
the call attachment facility OPEN request. 'Implicit' OPENs occur
when an application issues SQL statements before a DB2 connection was established. Correct the logic
in your application program.

Problem determination
 See a DSNTRACE trace stream to understand
the context of this message.