Download - Fall Back Switch
KUUMIC OY
DATA TRANSFER KU13.1
FALL-BACK SWITCHFBS KU13.1
Technical Reference
29.10.1996
KUUMIC OY
DATA TRANSFER KU13.1
CONTENTS
1. INTRODUCTION..............................................................................................................1
2. OPERATION LOGIC .......................................................................................................3
3. OPERATION MODES......................................................................................................4
3.1. Duplicated Lines ....................................................................................................................................................4
3.2. Duplicated Hosts....................................................................................................................................................5
3.3. Hot Standby ...........................................................................................................................................................6
3.4. Duplicated Hosts and Lines ..................................................................................................................................7
3.5. Fully Duplicated ....................................................................................................................................................8
4. HARDWARE DESIGN .....................................................................................................9
5. CONFIGURATION.........................................................................................................10
5.1. Power Supply.......................................................................................................................................................10
5.2. Common Line C...................................................................................................................................................11
5.3. Selectable Line .....................................................................................................................................................12
5.4. Settings .................................................................................................................................................................12
5.5. Indicators .............................................................................................................................................................13
6. APPENDIX.....................................................................................................................14
6.1. Layout ..................................................................................................................................................................14
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DATA TRANSFER KU13.1
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1. INTRODUCTION
The KU13.1 FBS (Fall Back Switch) is an Euro1-size unit for connecting RS-232communication links between modems and host computers and providing backup linesfor them. The FBS boards are installed in a 19” subrack: KU20 communication centerwhich can also hold Euro1-size modems KU18 and power supply unit. RS-232 and powersupply cables are connected via KU20 backplanes.
KU20 COMMUNICATION CENTER
POWER SUPPLY
OUTPUT OK
KU23
OM
IN
C
T
RO
TxD
RxD
FALL-BACKSWITCH
KU13.1
STANDBYSELECT
C
HOT
OM
IN
C
T
RO
TxD
RxD
FALL-BACKSWITCH
KU13.1
STANDBYSELECT
C
HOT
OM
IN
C
T
RO
TxD
RxD
FALL-BACKSWITCH
KU13.1
STANDBYSELECT
C
HOT
OM
IN
C
T
RO
TxD
RxD
FALL-BACKSWITCH
KU13.1
STANDBYSELECT
C
HOT
Several parts of the communication system can be duplicated with the KU13.1 FBS
SINGLE HOST - DUPLICATED LINES
MicroSCADA
C A
BFBSRS-232
RS-232
RS-232
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DATA TRANSFER KU13.1
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DUPLICATED HOSTS - ONE LINE
MicroSCADA
CA
B FBS RS-232RS-232
MicroSCADA
RS-232
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DATA TRANSFER KU13.1
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2. OPERATION LOGIC
Connects line Cto line B.
Connects line Cto line A.
yes
no
noIs there DTR/CD-signal on line A?
Connects line Cto line B.
yesTimeout?
Picture ku13I.drw
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DATA TRANSFER KU13.1
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3. OPERATION MODES
3.1. Duplicated Lines
FBS
HOST
M
M
M
M
FBSC
CASE 1 Duplicated lines
FBS activated by carrier detect
STATION
CA
B B
A
MicroSCADA
RS-232
A computer is connected to the connector C. The configuration switches S2-24 are setto DTE. The switch S25 is closed. These settings apply for both FBC’s.
As long as the CD signal is active on side A, the communication path is connected tothat side. When the CD signal is not detected on side A as the timeout delay expires,the communication path is switched to side B. The timeout delay is adjustable by trimmerR7.
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3.2. Duplicated Hosts
FBS
HOST
MODEM
MC
CASE 2 "Warm stand by"Duplicated host
FBS activated by A, DTR
STATIONA
B
HOST
A
B
MicroSCADA
RS-232
MicroSCADA
RS-232
MODEM
M
LINE
A modem is connected to the connector C. The switches S2-24 are set to DCE. Theswitch S25 is closed.
As long as the DTR signal is active on side A, the communication path is connected tothat side. When the DTR signal is not detected on side A as the timeout delay expires,the communication path is switched to side B. The timeout delay is adjustable by trimmerR7.
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3.3. Hot Standby
FBS
HOST
M MC
CASE 3 "Hot stand by"
FBS activated by last rising DTR
STATIONA
B
HOST
A
B
MicroSCADA
RS-232
MicroSCADA
RS-232
MODEM MODEMLINE
A modem is connected to the connector C. The switches S2-24 are set to DCE. Since theHot Standby mode is used, the switch S26 is closed.
The communication path is connected to the side, where the DTR signal is most recentlydetected. The initially active side (A or B) can be selected with switch S1.
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3.4. Duplicated Hosts and Lines
HOST
M
M
M
M
FBS
CASE 4 Duplicated hosts and lines
FBS activated by carrier detect
STATION
C
B
A
A
BHOST
MicroSCADA
RS-232
MicroSCADA
RS-232
MODEM MODEM
MODEMMODEM LINE
LINE
A computer is connected to the connector C. The switches S2-24 are set to DTE. Theswitch S25 is closed.
As long as the CD signal is active on side A, the communication path is connected tothat side. When the CD signal is not detected on side A as the timeout delay expires,the communication path is switched to side B. The timeout delay is adjustable by trimmerR7.
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3.5. Fully Duplicated
FBS
HOST
M
M
M
M
FBS
C
CASE 5 All duplicated
FBS activated by A, DTR and instation end by carrier detect
STATION
C
A
B
B
A
HOST
A
B
FBS
A
B
CMicroSCADA
RS-232
MicroSCADA
RS-232
RS-232
RS-232
MODEM
MODEM MODEM
MODEMLINE
LINE
A modem is connected to the connector C on both FBS’s. The configuration switches areset to DCE and the switch S25 is closed. A station is connected to connector C. Theswitches S2-24 are set to DTE. The switch S25 is closed.
The upper FBS selects the connection line according to the DTR signal on Host A. Whenthere is no signal detected during the timeout delay, the FBS connects the communicationto host B. This FBS connects the communication path according to the modem CD signal.When there is no signal detected on side A during the timeout delay, the FBS connectsthe communication path to side B.
The lower FBS works in the same way as the upper one, except that the first selection isHost B.
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4. HARDWARE DESIGN
The KU13.1 FBS is a solid state switch used to backup and connect communicationlines. The hardware is a single Eurosize card. The card has a built-in switching regulator.It accepts a power supply with a range of 7 - 33 VDC.
The receiver interface transforms the RS-levels to the TTL-levels and transmitter inter-face converts the TTL-signals to the RS-levels. The switching is made by the TTL- levels.
The Hot Standby mode is based on a Schmitt-trigger latch circuit. It can be preset withthe switch located on the front panel.
The timeout period is generated by a one shot timer chip. The timeout delay can beadjusted with a trimmer R7.
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5. CONFIGURATION
There are two D-connectors (D25S) for the selectable lines A and B, and RJ-45connector for the common line C. The common line C can also be connected to an on-board D-connector (D25S).
X4
X11
X2
AX6
21
X3
2X5
1
GND+V
ac
COMMONSELECT
1
B
C
5.1. Power Supply
The power line is connected to the backplane connector X5.The GND level is connected to the pin 2 and positive voltage to the pin 1. Thepower supply input voltage range is 7-33VDC.
2POWER SUPPLY
1
GND+V
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5.2. Common Line C
The common line C is connected to the backplane board as follows:
1 8
RJ45 FRONT VIEW
RJ4512345678
D-25P2282073254
Signal RICDDTRGNDRxDTxDCTSRTS
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The common line can be alternatively connected to the on-board D-connector. In thatcase, C = DTE.
pin 1 = PGpin 2 = TxDpin 3 = RxDpin 4 = RTSpin 5 = CTSpin 6 = DSRpin 7 = GNDpin 8 = CDpin 20 = DTRpin 22 = RI
5.3. Selectable Line
The selectable line is on the backplane board with the connector A or B. Theyare both D25-female connectors.
pin 1 = PGpin 2 = TxDpin 3 = RxDpin 4 = RTSpin 5 = CTSpin 6 = DSRpin 7 = GNDpin 8 = CDpin 20 = DTRpin 22 = RI
5.4. Settings
S1 LEFT on the Hot Standby mode triggers the connectionto line A
RIGHT on the Hot Standby mode triggers the connectionto line B
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DATA TRANSFER KU13.1
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S2-24 are always set to the same position depending on the C = DCE or DTE
C = DCE a modem is connected to the connector CC = DTE a computer is connected to the connector C
S25-27case A: S25 is closed, the timeout delay is activecase B: S26 is closed, Hot Standby modecase C: S27 is closed, Common Select mode
The Common Select mode slave boards change theirselections at the same time commanded by the masterboard.The master board S27 and S25 (timeout) or S26 (HotStandby) is selected.There is one master FBS board in thedatacommunication rack and one to four slave boards.The Common Select line is chained to every board.Ifmore than one backplane board is used, the CommonSelect line is chained to the next backplane board(X6).
5.5. Indicators
H1 upper line A TxDH1 lower line B TxD
H2 upper line A RxDH2 lower line B RxD
H3 upper line A DSRH3 lower line B DSR
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DATA TRANSFER KU13.1
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6. APPENDIX
6.1. Layout
S5S6
S3S4
C9S8S9
C10C17 S7C15
C8C16
C2C1
C44
S2
C43
C5C12
C46
C11C4
S25
S27
S26
C47C7C14C6
C13
C39
C45 C41
C42
C40
S18S19
S17
C38
C37
S22
S20S21
C31
C30
C23
C24
S12S13
S10S11
S15S16
S14
S23
C32
S24
C35
C36
C33
C34
C27
C19
C20
C25
C18
C26D1
C22
C21
C29
C28
R5
D7D6D5
X2N1
L1
V2C3
R7
R6
R4
+
R3
R2 V4D8
X1
V10
R8
R10
D9
D4
V11
RN1
H2
H1
H3
V7V6
R1 D10
V5R9
V8V9
V3
C = DTEC = DCE
V1
D3D2
R11 R12
S1
COMMON SELECT
CD
COMMON SELECT
HOT STAND BY
DTR
NC
ACTIVATED BY:
DIRECTION:
S26
S2-S24
S27
S25