IOS307I

Explanation
I/O to a device has timed out and been purged preventing
device initialization from completing.
In the message text: dddd
The device number.  

System action
The device is left offline. 

Operator response
Resolve the problem causing the I/O timeout
and issue the VARY dddd,ONLINE command.

Source
Input/output supervisor (IOS)

Module
IOSVNPTH

Routing code
2

Descriptor code
12