"Query/Reply: invalid input buffer"

Document ID : KB000027365
Last Modified Date : 14/02/2018
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The following error message can appear in the IDMS log:

 Query/Reply: invalid input buffer


When a VTAM terminal first connects to IDMS we check the VTAM MODE table entry used during LOGON (the LOGMODE). If the query bit is on in the LOGMODE, we send a 3270 "Read Partition Query" command to the terminal. The query bit is the second byte of the PSERVIC parameter in the LOGMODE entry; it will have a value of x'80' if it is on or x'00' if it is off.

The terminal should reply to the query with the capabilities it can support. The reply buffer should follow a specific format, if IDMS receives an invalid reply, it issues the "Query/Reply: invalid input buffer" error message . The reply buffer format is documented in the IBM 3270 Information Display System Data Stream Programmer's Reference, GA23-0059. You can decode the reply buffer that follows the error message using this information.

When this message is issued, the user at the terminal will notice that application map attributes are not as expected. For example, an application map normally uses reverse video and underscores but now it does not. This happens because IDMS takes default values for the attributes when the query reply fails, no extended attributes are used.

This error can be caused by VTAM terminals, PC emulation software or VTAM session manager software that does not support this feature or have not been configured properly to support it.

If you have difficulty determining the offending terminal you may want to contact CA Technical Support.

The solution requires fixing the software which generated the invalid reply buffer. As a workaround you can use a different LOGMODE entry which does not have the query bit on; or you can remove the query bit from the existing LOGMODE entry by changing the second byte of the PSERVIC parameter from x'80' to x'00'.

The drawback of using this workaround is that that mapping attributes will pick up default values, no extended attributes will be used.