The I-2532 CAN to Fiber Converter
Quick Start User Guide
1. Introduction
Fiber optic transmission medium is a good material to protect data
transmission from EMI/RFI interference and has been used in harsh
environment extensively. CAN bus is famous in industrial application.
More and more users build CAN networks to communicate their
controllers, sensors and actuators. In order to solve the problem between
different transmission medium, I-2532 is specially designed for converting
the electrical CAN bus signal to fiber optic cables.
The fiber length between two I-2532s can be up to 1.4km (4593ft), it is
mainly decided by the cable attenuation of fiber and the CAN bus baud. I-
2532 is the economic solution for applications which require protecting the
data transmission from electrical exposure, surges, lightning or chemical
corrosion. Generally, I-2532 can be used in CANopen, DeviceNet and all
the other CAN network which follows the ISO 11898-2 standard.
CAN Device
CAN Device
I-2532
I-2532
ISO 11898-2
CAN Device
Fiber
ISO 11898-2
CAN Device
Up to 1.4 Km
62.5/125 µm multimode Fiber
Cable Attenuation of Fiber < 2.8 dB/Km
This quick-start describes how to implement the I-2532 module into
users’ applications in a quick and easy way. Therefore, it only provides the
basic concepts. If users want to know more detail information about the I-
2532, please refer to the user manual of I-2532 in the product CD or visit
our website as follows:
I-2532 CAN to Fiber Converter Quick Start User Guide (ver. 1.1, 2008/10/03) -----1
4. LED Indicators & Terminal Resistance
The table below shows the meanings of LED indicators on the I-2532.
Transmitting/receiving one message to/from fiber cable will flash the
TD/RD LED once. The TD/RD LED may always be turned on if there are
a lot of messages transmitted on fiber cable.
POWER LED
(Red Light)
TD LED
(Green Light)
RD LED
(Green Light)
module
messages
messages
on
flashing
off
flashing
off
active
transmitting
receiving
module
inactive
no message
transmitting
no message
receiving
off
The switch at bottom of I-2532 is used for adjusting terminal
resistance (120Ω) on CAN Port. The switch functions are shown below.
Active
Inactive
(Enable)
(Disable)
5. Wire Connection
Metallic
Board
Fiber
Tx
Tx
Rx
Rx
Interconnecting
CAN_GND
CAN_H
CAN_GND
+10VDC ~ +30VDC
Power GND
+10VDC ~ +30VDC
Power GND
CAN_H
CAN_L
CAN_L
Earth Ground
Earth Ground
ISO 11898-2
ISO 11898-2
Roughly speaking, wiring of CAN_GND and FG can improve the
capability of anti-interference of CAN bus system, but this is not necessary.
I-2532 CAN to Fiber Converter Quick Start User Guide (ver. 1.1, 2008/10/03) -----3
6. Bus Length & Fiber Length
Higher attenuation of fiber will reduce the transmission distance. Users
can use following table to know the relationship between those two.
Attenuation [dB/km] Ideal Fiber Length [m]
2.8
4
<1400
<400
The limitation of baud on a CAN network is restricted by propagation
delay. On the other hand, long bus length leads to long propagation delay.
The relationship between baud and bus length is displayed below.
Baud [bit/sec]
500K
Ideal Bus Length [m]
< 100
< 250
250K
125K
< 500
50K
20K
10K
< 1000
< 2500
< 5000
The definition of segments the relationship between segment length
(LSEG1, LSEG2 …) and bus length (LBUS) in the same CAN bus system are
shown in the following figure.
LBUS = Lseg1 + Lseg2 + Lseg3
Lseg1
Lseg2
Lseg3
ISO 11898-2
Fiber
ISO 11898-2
I-2532
I-2532
When users add one pair of I-2532 into a CAN bus system, the ideal
bus length will reduce 50 meters because the propagation delay of one I-
2532 is equal to the propagation delay caused by 25 meters bus length.
For example, if users use baud 50Kbps and add two I-2532s into the CAN
network, the ideal bus length should less than 950 meters (1000-
25*2=950).
I-2532 CAN to Fiber Converter Quick Start User Guide (ver. 1.1, 2008/10/03) -----4
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