PSI BOX PLUS+ Reference
Control Functions
CONFIGURE.
Specifies Devices Parall Poll Response.
_________
__________________________________________
Purpose.
This command is used to instruct one or more
__________
devices as to how they should respond to a parallel poll.
Devices respond to a parallel poll command by asserting a
particular data line high or low, this informs the PSI BOX
whether the device requires the services of the controller. A
device cannot respond to a parallel poll command unless it has
been configured by either the CONFIGURE command or by the
PPC PPE sequence. This CONFIGURE command is a straight
forward means of assigning a data line, for response to the
parallel poll command, to the specified device.
The PSI BOX addresses the specified device performs the
PPC PPE sequence as explained in the PPE command
explanation.
As well as the device address the CONFIGURE command
requires a number in the range 0-15. This parameter has the bit
value %0000sppp. Here s is the sense of response bit and ppp is
the data line assigned to the device.
The sense information is in bit 3 (decimal 8).
If bit 3=0 then assert line when the device’s individual status bit,
IST, is zero.
If bit 3=1 then assert line when the device’s IST is one.
The data line is assigned using bits 0-2.
If bits= 000, decimal 0, then data line 0
If bits= 001, decimal 1, then data line 1
If bits= 010, decimal 2, then data line 2
If bits= 011, decimal 3, then data line 3
If bits= 100, decimal 4, then data line 4
If bits= 101, decimal 5, then data line 5
If bits= 110, decimal 6, then data line 6
If bits= 111, decimal 7, then data line 7
Format.
CONFIGURE ad+sppp
_________
Params.
Two or more
_________
Returns.
None.
__________
Page 92
Chapter 8
