Xerox 7120 - Card Reader Event Times

Time (in milliseconds)
Event
·0
-,--,-------Card reader receives valid read order and reader is in "busy automatic" state. Light check
10 C
20-~.
occurs at this time. If light check fails, the read indicator will light, the reader will switch
to
"not operational" and an "unusual end" will be signaled to the controlling system.
I-~
30 -tl-f----....;;...,---Column 1 arrives at read station. Mode change (EBCDIC to binary) will occur at this time if
40 _ rows 1 and 2 are punched.
50 -
60 -
70 -
B
80 -
90 -
100 -
110 -
-l~---'------- Column 80 arrives at read station.
120 -
130 -
140
--1-------0
End of card is detected; card reader signals "channel end" to controlling system. Card reader
returns to "ready" condition (a new SIO can be accepted if no interrupt is pending) unless the con-
trolling system specifies command chaining, in which case the reader requests a new read order.
150
-"1 ________ New feed cycle enabled at this time if new valid order present and reader still in "automatic"
Notes:
®
®
©
@
mode.
Feed
cycle is approximately27ms if card feeds on first attempt, approximately 87ms if card feeds on
second
attempt, and approximately 147ms if card feeds on third attempt. If a card has not been fed after
three attempts, the transport motor will halt, the reader will switch to "not operational", the FEED
indicator will light, and an "unusual end" will be signaled to the controlling system.
The
data bytes are transmitted, with respect to the col urnn read time (approximately 1.12 ms), as shown below.
1- 1 .12 ms -1- 98 ms -I
Data available to controlling system ~
t
U U
1
EBCDIC mode: Transmit one byte
for each column
~,-- ___ n,-- __ ----,n,-- __
~ nJl n'----_
Binary mode: Transmit rows 12-5 ____ ---'1 t r
Store rows 6-9 I ~- ---Transmit rows 2-9
Transmit rows 12-1 plus
rows
6-9 of previous column
t indicates data overrun will occur at this time if data is not accepted by controlling system.
Throat jam
detection occurs 125 ms later if card jams in throat area, causing transport motor to halt, FEED
indicator to light, reader to switch to "not operational", and an "unusual end" to be signaled to the
controll ing system.
Read and timing jam
detection occurs 125 ms later if card jams in read and timing area. Results in same
action as © above.
® Dark check occurs at this time. If dark check fails, the READ indicator will light, the reader will switch
to
"not operational", and an "unusual end" will be signaled to the controlling system.
® Stacker jam detection occurs 125 ms later if card jams in stacker area. Results in same action as © above.
Figure 6. Card Reader Event Times (Model 7122)
14 Programming Considerations
All manuals and user guides at all-guides.com