Casio Qt2100 User Manual

							I-11QT-2100 Installation & Down Recovery Manual
2. System down and recovery
In the QT-2100 system, the check tracking system has their master and backup master and
remote printer printing system has their master printer and backup master printer. If both
masters (or corresponding printers) go down, the check tracking system, and remote printer
printing system cannot continue any processing. Therefore, the system must be designed
such that even if the master goes down, their processing remains unaffected. The QT-2100
system whose master and backup master, respectively, have files for above systems
simultaneously updates their counter/totalizer/work area during operations. If the master
goes down, control is automatically transferred (only the remote printer printing system)/
the control is manually transferred (check tracking system) to the backup master,
preventing their operation from being interrupted.
Nevertheless, system reliability should be improved so as to minimize the possibility of
system failure. Poor system reliability disables the system to work efficiently. System
reliability could be improved by the following method.
1) Use reliable system components.
2) Design reliable circuitry.
3) Make sure that trouble with the system can be remedied easily.
4) Provide complete backup to minimize damage caused by trouble.
Item 1) and 2) are concerned with hardware design. Needless to say, they were given the
utmost consideration in designing the QT-2100 system. Item 3) is related to software
design. As an effective solution to these problems, the QT-2100 offers a diagnostic routine
and backup functions.
This section describes the measures provided by the system to prevent trouble, the system
function performed when the system goes down, and the method of system recovery. 
						

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Down Recovery
2-1. Measures to prevent trouble
The QT-2100 system hardware boasts exceptional reliability. However, no machine can
be completely free from trouble. When a given system can predict a possible trouble or
permits a failing point to spotted easily, the time required for repair can be cut and
consequently, the overall system reliability can be improved.
The QT-2100 system offers a self-diagnostic program for servicemen to enable individual
devices to be checked at the terminal level. For a detailed description of this program, see
the QT-2100 Service manual.
If a system error occurred during an actual operation, error informations output to the
terminal display.
Trouble with the terminal CPU can be fatal to the system. In this case, it is impossible even
to obtain an error log. As long as the number of retries is within a predetermined limit, the
processing being performed is not interrupted. By the time the processing is interrupted,
error information is logged, so that the serviceman can repair or replace defective parts
before the system goes down.
To summarize,
1) Terminal-level hardware check:
Self-diagnostic program.
2) Error information, etc. during in-/online data transmission:
The error is displayed on the master terminal display and logged in the error log file.
3) Abnormal completion of processing due to error:
An error message is output to the terminal display.
Needless to say, a backup master is indispensable, since trouble with the master can lead
to system down. In the QT-2100 system, both the master and backup master have the check
tracking system, the files are updated simultaneously (main-mirror system). Thus, even if
either master goes down, the index and detail data remain intact. 
						

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2-2. Master terminal failure
The master has important files, such as check tracking files. If the master terminal goes
down, the following undesirable condition results:
1) The check tracking processing (open check, close check. etc.) being performed cannot
be continued. (In case of Check Tracking master goes down.)
2) The receipt cannot be printed out to remote printers. (In case of Remote printer master
goes down.)
If the master terminal failed, therefore, the user should call the serviceman as soon as
possible.
2-2-1. Check tracking master terminal failure
2-2-1-1. Detection of check tracking master terminal failure
With the QT-2100 system, the satellite terminal assumes that the master terminal is down
when it could not obtain any response to its inquiry. The master terminal is assumed to have
gone down in the following cases:
1) The power cable is disconnected from the outlet.
2) Trouble with the inline between the master and the satellite terminal.
3) Trouble with the master terminal hardware.
Note that the master terminal is not really down in the first two cases.
When a satellite detects the master terminal down, the satellite displays the “try again?”
message. If the operator of the satellite disapproves this proposal, the satellite turn on the
“Master down” flag and broadcast all of the terminals (including backup master) connected
inline. After broadcasting this flag, all of the terminals do not access any check tracking
data to the master.
Operation when detecting master down
1. When the terminal detects master down, the message appears
on the screen.
REG C01        10-10-01 12:34    000001
     MC #01
     E105 Check/TBL tracking Master
          down.
          Please call Manager!!
      YES:Retry for connection.
      NO :Remove it from system.
NEW/OLD       123456
←Machine No. of master 
						

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Down Recovery
2. Selecting “YES” retries communication with the master.
Selecting “NO” turns on the master’s down flag and broadcast
it to all of the terminals. Then the “Cut off Master/BM icon”
is lit.
Note:
Do not press “No” key unless attempting “Retry” operation.
Press “ Yes” key to retry to send data to master terminal
when the error message is shown on the display.
3. When there is no backup master, this message will appear on
the display.
2-2-1-2. Master failure during check tracking operation
1The satellite makes an inquiry about check tracking data, but it cannot obtain any
response from the master.
2If “No” key is pressed on the above situation, the satellite turns on its own “Master
Down” flag and broadcast this flag all of the terminals. The “Cut off Master/BM icon”
of all terminals received this flag are lit.
3Then the satellite makes an inquiry to the backup master.
Note:
When the backup master goes down, the satellite turns on the “Backup master Down” flag
and makes no further inquiry to the backup master.
SatelliteSatellite Master
Backup
master
Check
trackingCheck
tracking
1
2
3
REG C01        10-10-01 12:34    000001
     MC #01
     E108 CHK/TBL Master is removed
          from system.
NEW/OLD       123456
 !
←Machine No. of master
←Cut off Master/BM icon
REG C01        10-10-01 12:34    000001
     E107 Both Master&Backup master
          down. CHK/TBL tracking or
          Clerk interrupt is not
          available. 
						

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2-2-2. Remote printer failure
2-2-2-1. Detection of remote printer failure
With the QT-2100 system, the satellite terminal assumes that the master printer is down
when it could not obtain any response to its inquiry. The master printer is assumed to have
gone down in the following cases:
1) The power cable is disconnected from the outlet (the terminal or the printer).
2) Trouble with the inline between the terminal connected with the master remote printer
and the satellite terminal.
3) Trouble with the connection between printer and terminal.
4) Trouble with the terminal hardware connected with the master printer.
5) Trouble with the printer hardware.
Note that the master terminal or the remote printer is not really down in the first three cases.
When a satellite detects the master printer down, the satellite sends the data to the backup
printer automatically. (No operation is necessary at the terminal.)
2-2-2-2. Master printer failure during printing on remote printer
1The terminal requires an inquiry about the printing data, but it cannot obtain any
response from the terminal with remote master printer.
2Then the terminal makes an inquiry to the terminal with remote backup printer.
3The terminal broadcasts remote printer down data to all terminals of the system.
Note :
When the remote backup printer or the terminal with remote backup printer goes down,
there is an option to retry printing/to display on the screen/to discard data.
TerminalTerminalTerminalw/ remote prtTerminalw/ remote prt
1
2
3
Remote
master
printerRemote
backup
printer 
						

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Down Recovery
2-3. Recovery processing
With the QT-2100 system, the processing being performed can be continued by a backup
master even when a master goes down. However, at the end of the daily operations, the
master which has been down should be restored so that it can operate normally on the next
day.
2-3-1. Master/backup master down detection
1) After daily operations, check the “Cut off Master/BM” icon.
2) If the icon is lit on any terminal, the system has been downed in the day.
3) Turn off/on the master and backup master (not by the  key but by the power
switch bottom side of QT-2100).
4) After this operation, the “System error” icon is lit on the master (or backup master) or
both master/backup master.
5) In case of the icon of one terminal is lit, disconnect this terminal from the inline and
repair it. If the icon of both terminal are lit, both master have been downed. This case,
jump to the next section.
6) Connect the restored master terminal with the inline, initialize it and download the
terminal program from the other master.
7) Perform the “System Re-configuration” at the good (not downed) master terminal.
2-3-2. When both master and backup master go down
1) Restore both masters immediately, load the program file to them.
2) Perform the “System Re-configuration” at the master terminal.
2-4. Master failure during X/Z collection/consolidation or terminal data transfer
With the master goes down during X/Z collection/consolidation or transfer of terminal
program file, it is necessary to take the following procedure:
1) When the master goes down during Z collection/consolidation, the satellite is not
released from locked condition.
2) In this case, press the  key twice to release the locked condition.
3) After step 2), cut off the downed master from the system connection table and perform
Z collection/consolidation from other terminal.
This command should be issued by the good (not downed) terminal.
2-5. Satellite terminal down
When the satellite terminal goes down during check tracking registration, the check
number cannot be used for other terminal.
In this case, performing the “Busy Reset” command in the manager mode releases this flag. 
						

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							CASIO COMPUTER CO., LTD.
6-2, Hon-machi 1-chome
Shibuya-ku, Tokyo 151-8543, JapanIR0202-003001-A
Printed in Japan
QT-2100IM*E
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