MPE/iX Commands Reference Manual (32650-90877)

156 Chapter5
Command List III
Commands DATA thru EXIT
Related Information
Commands ASSOCIATE
DISCRPS
Enables or disables the rotational position sensing (RPS) feature on a specified logical
device. It requires a special firmware upgrade CS-80 disk drives.
Syntax
DISCRPS
ldev { ,ENABLE [{, value,value }] ,DISABLE }
Parameters
ldev The logical device number of the specified CS-80 disk drive.
ENABLE Enables rotational position sensing on the device.
DISABLE Disables rotational position sensing on the device.
value Allows the time-to-target and window size to be tuned, in hundreds of
micro seconds. If you specify one value you must specify both values. The
first is interpreted as the time-to-target value; the second is interpreted as
the window size value. This parameter only works in conjunction with
ENABLE.
(micro seconds)
Default time-to-target 90 (9000 )
window size 30 (3000 )
ONLY use this parameter if you have a clear understanding of its meaning and
implications.
Operation Notes
The DISCRPS command allows you to enable or disable the rotational position sensing
feature for CS-80 disk drives. With RPS enabled, the disk drive signals its availability to
do an I/O only when it is a small rotational distance away from the target data. This
improves system performance when more than one drive is connected to the same HP-IB
channel.
Use
This command may be issued from a session, job, program, or in BREAK. Pressing
Break
has no effect on this command. It may be executed only from the console unless distributed
to users with the ALLOW or ASSOCIATE commands.