ICP DAS USA I-2532 - Manual (Page 4)

I-2532 CAN to Fiber Converter Quick Start User Guide (ver. 1.1, 2008/10/03) -----4
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 <1400
4 <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] Ideal Bus Length [m]
500K < 100
250K < 250
125K < 500
50K < 1000
20K < 2500
10K < 5000
The definition of segments the relationship between segment length
(L
SEG1
, L
SEG2
…) and bus length (L
BUS
) in the same CAN bus system are
shown in the following figure.
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).
Fiber
I-2532 I-2532
ISO 11898-2 ISO 11898-2
L
seg1
L
seg2
L
seg3
L
BUS
= L
seg1
+ L
seg2
+ L
seg3