Card Reader Event Times (Model 7120) - Xerox 7120 Reference Manual

Time (in milliseconds)
Event
o _----r---r----------
Card reader receives valid read order and reader is in "busy automatic" state.
10
20
B
30
40
1----1-----------
Column 1 arrives at read station. Mode change (EBCDIC to binary) will occur at
50
60
70
80
90
100
110
120
130
140
C
this time if rows 1 and 2 are punched.
Column 80 arrives at read station.
End of card is detected; card reader signals "channel end
ll
to controlling system.
Card reader returns to
II
ready'. condition (a new
510
can be accepted if no in-
terrupt is pending) unless the controlling system specifies command chaining, in
which case the reader requests a new read order.
150~~-------------
Card advances from read station to stacker station. New feed cycle begins at
this time if new valid order is present and reader is still in the lIautomatic
ll
mode.
160+--It------------- Card is stacked in preselected stacker or in error stacker (alternate 2).
Notes
®
If the feed cycle begins while the previous card is being stacked, a stacker transport jam occurring in this time
interval causes the reader to stop the transport motor, switch to IInot operational II, light the FAULT indicator,
and signal lIunusual end ll to the controlling system.
®
Feed cycle (approximately 43 milliseconds).
©
The data bytes are transmitted, with respect to the column read time (approximately 1.34 milliseconds), as follows:
Column read pu Ises
EBCDIC mode:
Binary mode:
odd column even column odd column
transmit one byte
for each column
Transmit rows 12-S
J
Save rows 6-9
l
Transmit rows 2-9
Transmit rows 12-1 plus rows
6-9 of previous column
©
If stacker jam occurs after new feed cycle begins, action during this interval is identical to note A. If stacker
jam occurs before new feed cycle begins, reader turns off transport motor, switches to IInot operational
ll
state,
and lights FAULT indicator ("unusual end" is not signaled in this case).
Figure 4. Card Reader Event Times (Model 7120)
12 Programming Considerations