Cabletron Systems FOT-DF24 Manual

Transmit (XMT) 

This green LED flashes when the

FOT-DF24 transmits data. The LED flash is pulse

stretched for viewing effect. The XMT LED is off when

the device is active but not transmitting.

Receive (RCV)

 This yellow LED flashes when the

FOT-DF24 receives data from the network. If attached

to a repeater, RCV flashes when data passes through

the FOT-DF24. The LED is pulse-stretched for viewing

effect.

Collision (CLN) 

This red LED flashes when the

transceiver detects a collision condition or a jabber

packet on the network. The flash frequency may

increase as network traffic increases since more

collisions are likely to occur. The LED is pulse-

stretched for viewing effect.

Link OK (LNK) 

When lit, this green LED indicates that

a link exists between the FOT-DF24 and the device at

the other end of the fiber optic segment. LNK remains

lit as long as the link is maintained. To maintain the

link, the transceiver generates a 1 MHz idle signal

when it is not transmitting data. Both ports can show a

valid link.

Active Port (ACT)

 This yellow LED indicates which

fiber optic port is handling all network traffic through

the transceiver. Only one por t can be active; the

inactive port ACT LED is off. A flashing ACT LED

indicates that the port is in the idle state. A slow flash

indicates that the time-out period is set to 10 seconds;

a fast flash indicates that the time-out period is set to

2 seconds.

GETTING HELP

If you have questions, or need additional help, contact

Cabletron Systems Technical Support as follows:

By phone:

Monday through Friday,

8 am to 8 pm EST at

(603) 332-9400

By CompuServe:

GO CTRON from any ! prompt

By Internet mail:

support@ctron.com

LANVIEW 

is a registered trademark of Cabletron

Systems, Inc.

FOT-DF24 

is a trademark of Cabletron Systems, Inc.

CompuServe 

is a registered trademark of 

CompuServe, Inc.

Ethernet

 is a trademark of Xerox Corp.

FCC NOTICE

This device complies with Par t 15 of the FCC r ules.

Operation is subject to the following two conditions: (1) this

device may not cause harmful interference, and (2) this

device must accept any interference received, including

interference that may cause undesired operation.

NOTE: This equipment has been tested and found to comply

with the limits for a Class A digital device, pursuant to Part 15

of the FCC rules. These limits are designed to provide

reasonable protection against harmful interference when the

equipment is operated in a commercial environment. This

equipment uses, generates, and can radiate radio frequency

energy and if not installed in accordance with the operator’s

m a n u a l ,   m ay   c a u s e   h a r m f u l   i n t e r fe r e n c e   t o   r a d i o

communications. Operation of this equipment in a residential

area is likely to cause interference in which case the user will

be required to correct the interference at his own expense.

WARNING:

 Changes or modifications made to this device

which are not expressly approved by the party responsible for

compliance could void the user’s authority to operate the

equipment.

DOC NOTICE

This digital apparatus does not exceed the Class A limits for

radio noise emissions from digital apparatus set out in the

Radio Interference Regulations of the Canadian Department

of Communications.

NOTICE

Cabletron Systems reserves the right to make changes in

specifications and other information contained in this

document without prior notice. The reader should in all cases

consult Cabletron Systems to determine whether any such

changes have been made. The hardware, firmware, or

software described in this manual is subject to change

without notice.

IN NO EVENT SHALL CABLETRON SYSTEMS BE LIABLE

F O R   A N Y   I N C I D E N TA L ,   I N D I R E C T,   S P E C I A L ,   O R

C O N S E Q U E N T I A L   DA M A G E S  W H AT S O E V E R

(INCLUDING, BUT NOT LIMITED TO, LOST PROFITS)

ARISING OUT OF OR RELATED TO THIS MANUAL OR

T H E   I N F O R M AT I O N   C O N TA I N E D   I N   I T,   E V E N   I F

CABLETRON SYSTEMS HAS BEEN ADVISED OF, KNOWN

OR SHOULD HAVE KNOWN, THE POSSIBILITY OF SUCH

DAMAGES.

© Copyright August 1994 by

Cabletron Systems, Inc.

P.O. Box 5005, Rochester, NH 03866-5005

All Rights Reserved

Printed in the United States of America

Part number: 9030729-02 August 1994

FOT-DF24

802.3 10BASE-FL/FOIRL

Redundant Transceiver 

The FOT-DF24™ fiber optic transceiver is designed to

link two Ethernet™ devices through fiber optic cable.

Dual fiber optic ports with ST type connectors provide

redundant data paths for critical applications.

If the primary port (port 1) receives no data for either 2

or 10 seconds (switch selectable), the port enters the

idle state. During the idle state, if the back-up port

(port 2) receives data it becomes the active port.

When the primary port senses data again, it switches

back to become the active port. The two transceiver

ports can be connected to the same network device,

different network devices or even different networks.

REQUIREMENTS

The FOT-DF24 Transceiver complies with IEEE 802.3

10BASE-FL/FOIRL specifications. Use the FOT-DF24

w i t h  Ve r s i o n   1 ,  Ve r s i o n   2 ,   a n d / o r   I E E E   8 0 2 . 3

equipment. For best network performance, observe

the following network guidelines.

Fiber Optic Requirements

The FOT-DF24 supports 50/125 

µ

m, 62.5/125 

µ

m, and

100/140 

µ

m fiber optic cable. Link length depends on

cable type and system fiber optic budget. The FOT-

DF24 supports a maximum link length of 2 km.

FOT-DF24

802.3 10BASE-FL/FOIRL

REDUNDANT TRANSCEIVER 

WITH 

LANVIEW®

P

W

R

S

Q

E

X

M

T

R

V

C

C

L

N

SN

LNK

ACT

TX

RX

LNK

ACT

TX

RX

MIN    MAX

SQE

Primary Port

Back-up Port

1

2