Control Functions
PSI BOX PLUS+ Reference
TO.
Set The Timeout Period.
____
_____________________
Purpose.
To set the length of time the PSI BOX will wait in a
__________
bus handshake routine till the responding device is ready for the
data transfer. This prevents the PSI BOX hanging up when the
device is not ready.
When the PSI BOX is exchanging data with a bus device
it may need to wait a long time for the data to become present,
or for the device to make data available. The TO command can
be used to set the maximum time that the PSI BOX waits for
the device to become ready, thus preventing the PSI BOX
waiting for too long when a device is not ready. By contrast, the
NO TO command can be used to make the PSI BOX wait
indefinitely for the device to be ready to handshake data.
The TO parameter is used to determine the length of wait
before the PSI BOX times the device out.
Bytes 57 and 58 in the IEEE control status string contains the
current timeout value.
A value of 0 indicates that the timeouts have been disabled.
The timeouts step up in 1,2,5,10 increments from 1 milli second
to 50 seconds. Therefore each timeout increment represents an
increase in PSI BOX wait time of approximately a factor of 2.
The timeouts can also be disabled using NOTO or by TO 0.
Format.
TO
_________
Params.
One in the range 00 to 15.
_________
Returns.
The IEEE string holds the current timeout value in
__________
position 57-58.
NO TO gives a TO value of 0, means wait forever.
TO 0
Means wait forever.!!! careful!!
TO 1
1
milli second wait till timeout.
TO 2
2
milli second wait till timeout.
TO 3
5
milli second wait till timeout.
TO 4
10
milli second wait till timeout.
TO 5
20
milli second wait till timeout.
Chapter 8
Page 155
Содержание P.S.I. BOX
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