090

Explanation
The error occurred during processing of a basic
telecommunications access method (BTAM) OPEN macro. An OPEN routine
found that a device other than a communications device was allocated
to the data control block (DCB) being opened. That is, the device
class code in the unit control block (UCB) for the device allocated
to the data control block was not equal to X'40'.

System programmer response
If the error recurs and the program
is not in error, look at the messages in the job log for more information.
Search problem reporting data bases for a fix for the problem. If
no fix exists, contact the IBM® Support
Center. Provide the JCL and the program listing for the job.

Programmer response
Either the UNIT parameter of the DD statement
for the communications device is incorrect or the UCB generated during
system generation is incorrect. Check for improper specification of
the UNIT parameter or the IODEVICE macro used in generating the system.
 Also, check for program errors that could have improperly modified
control information.  After correcting the error, run the job step
again.

Source
Teleprocessing