Measurement Computing Digital HS - Manual (Page 39)

3.4 Parallel Polling
The Digital488HS/32 provides the method by which the individual status message
(ist), either "true" (1) or "false" (0), can be determined by parallel poll.
ist is set true or false according to the setting of the ist EN Full switch (S2-2), the ist
EN Empty switch (S3-2), and the current states of the input and output ports. The
three least significant address IEEE 488 bus address switches (labeled 1, 2 and 4)
determine which bus DIO line the Digital488HS/32 uses to report the status. The
following table illustrates the Address Switch, ist status and the DIO line used.
0
1
0
0
0
0
0
0
0 –
–
–
–
–
–
–
–
– –
–
–
–
–
–
–
–
– –
0
0
0
0
1
1
1
1 –
0
0
1
1
0
0
1
1 –
0
1
0
1
0
1
0
1 0
1
1
1
1
1
1
1
1
ist
0
0
0
0
0
0
0
0
1 0
0
0
0
0
0
0
1
0 0
0
0
0
0
0
1
0
0 0
0
0
0
0
1
0
0
0 0
0
0
0
1
0
0
0
0 0
0
0
1
0
0
0
0
0 0
0
1
0
0
0
0
0
0
IEEE Bus Address Switch Status Parallel Poll Response
DIO8 DIO7 DIO6 DIO5 DIO4 DIO3 DIO2 DIO1 S1-4 S1-5 S1-6 S1-7 S1-8
The following table shows the status enable switch settings, the status conditions and
the corresponding individual status message (ist).
ist
Output Input ist EN Full S2-2
–
–
–
Full
Not Full
Full
Not Full
Full
Not Full
Disabled
Disabled
Disabled
Enabled
Enabled
Enabled
Enabled
Enabled
Enabled
–
Empty
Not Empty
–
–
Empty
Empty
Not Empty
Not Empty
Disabled
Enabled
Enabled
Disabled
Disabled
Enabled
Enabled
Enabled
Enabled
0
1
0
1
0
1
1
1
0
ist EN Empty S3-2 ist