Poll Response Frames - IBM 5256-1 Maintenance Information Manual

Poll Response Frames
Frame 1 is a 1-frame response sent to the controller
after the printer has been polled following a power on
reset. The controller receives frame 1 and returns a 'set
mode' command.
A 2-frame response is sent for every 'poll' command
following a 'set mode' command defining the interframe
fill length. Poll response frame' 1 contains the following
information:
ITII'I~1118191101~11411il
Fill Parity Busy Sync
Printer Address
Bit
Odd/Even
Response
Level
Exception Status
Outstanding Status
Line Parity (04) Unit Not Available (51)
Bit 7:
0= Not busy
1 = Busy
Bit 8:
o
= No line parity error
1 = Line parity error (04)
Bit 9:
o
= Unit available (The Ready light is on.)
1 = Unit not available (51)
Bit 10:
o
= No outstanding status
1 = Outstanding status (available by using the 'read
status' command)
Bits 11, 12, and 13:
Bits 11, 12, and 13 indicate exception status as follows:
Bit
11 12 13 Meaning
0 0 0 No exception status
0 0 1
Activate lost (parity)
0 1
0 Invalid activate command (24)
0 1
1 Not used
1 0
0 Invalid command or device ID (20)
1 0 1 Input queue or storage overrun (22)
0 Not used
Power on transition (08)
Bit 14:
By analyzing bit 14, the controller determines whether
the information in the response frame is the same as
that in the previous response frame or if the
information has changed. Bit 14 is turned off after
power on. Any change in the response frame
changes bit 14 from its previous state.
Frame 2 contains the following information:
I
T
III~ 17181911011111211311411~1
Fill Parity
I
End of Message
Invalid SCS Control
Character (28)
Invalid SCS
Parameter (29)
Receive Buffers Full
Theorv,
Features
Sync
Bit
Graphic
Check (26)
End of
Forms (50)
Print Mechanism
Not Ready (30
Cancel Request
Print Complete
Theory 5256 MIM 4-9