I have a question related to Mode Parameters.  I have searched SPC-4 (and earlier SPC versions) and cannot find guidance about when the changes to mode parameters take effect.  This concern is related to configuration settings and differences in expectations of various vendors.

Vendor 1 claims that any change to a mode parameter shall become effective immediately and should not cause a device to reboot.
Vendor 2 claims that changes to some mode parameters require a reboot before they can be accomplished.  As such the device automatically performs a POR on completion of the Mode Select that changes one or more of these parameters.
Vendor 3 also claims that changes to some mode parameters require a reboot before they can be accomplished.  This device,however, requires that an outside entity send a command to force the device to perform a POR.  The new values of the mode parameters are not in effect until after the POR.

In another form of when do parameters take effect, the requested change to the format (or density) does not occur until a subsequent command (e.g., a Format, a Write from BOT, etc.).

Is there any guidance in SPC?

Thanks,

Kevin D. Butt
SCSI & Fibre Channel Architect, Tape Firmware
MS 6TYA, 9000 S. Rita Rd., Tucson, AZ 85744
Tel: 520-799-2869 / 520-799-5280
Fax: 520-799-2723 (T/L:321)
Email address: kdbutt@us.ibm.com
http://www-03.ibm.com/servers/storage/