ICP DAS USA CAN Repeater I-7531 User manual

i-7531 CAN Repeater User Manual (ver. 1.2, 2008/02/13) ------1
User’s Manual
Warranty
All products manufactured by ICP DAS are under
warranty regarding defective materials for a period of one
year from the date of delivery to the original purchaser.
Warning
ICP DAS assumes no liability for damages resulting
from the use of this product. ICP DAS reserves the right to
change this manual at any time without notice. The
information furnished by ICP DAS is believed to be
accurate and reliable. However, no responsibility is
assumed by ICP DAS for its use, or for any infringements
of patents or other rights of third parties resulting from its
use.
Copyright
Copyright 1997 by ICP DAS. All rights are reserved.
Trademark
The names used for identification only may be
registered trademarks of their respective companies.
The
i
-
7531 CAN
Repeater

i-7531 CAN Repeater User Manual (ver. 1.2, 2008/02/13) ------2
Tables of Content
Tables of Content...........................................................................................2
1Introduction.............................................................................................3
1.1 Features..........................................................................................4
1.2 Specifications.................................................................................4
1.3 Application.....................................................................................4
2Technical data.........................................................................................5
2.1 Block Diagram................................................................................5
2.2 Appearance....................................................................................6
2.3 Pin Assignment..............................................................................7
2.4 Wire Connection ............................................................................9
2.5 Status LED....................................................................................10
2.6 Terminator Resistor Setting........................................................10
2.7 Cable Selection............................................................................12
2.8 Driving Capability and Baud.......................................................13
3Application Architecture ......................................................................15
4Dimension and Mounting.....................................................................16

i-7531 CAN Repeater User Manual (ver. 1.2, 2008/02/13) ------3
1 Introduction
The i-7531 is a CAN repeater used to establish a physical coupling of two
or more segments of a CAN bus system. User can implement tree or star
topologies as well as for long drop lines with i-7531. Connecting via i-7531, the
division of a CAN system into several subsystems increases the maximum
number of bus nodes.
CAN Network
Ethernet
NoteBook
i-7540D
i-7530
RS-232
SCADA
(Indusoft)
i-87 20/i-8 20
(RS233/CAN
converter)
(CAN Interface Slot Module) i-7531
Extend CAN line
CAN Network
(Ethernet/CAN
converter)
Figure1. Application of i-7531
The i-7531 is an optically isolated CAN repeater which provides 2500 Vrms
of optical isolation allowing you to separate and protect critical segments of the
system from the rest of the CAN network. And its galvanic isolation isolates
both CAN segments from each other as well as from the power supply The
CAN connection of i-7531 is by terminal blocks. A power supply of 10 ~ 30 DC
voltage is required. The i-7531 is housed in a rugged DIN-Rail mountable box,
making it easy to install in an industrial cabinet. Therefore, i-7531 can be used
in CANopen, DeviceNet and generic ISO 11898-2 standard.
If user wants to know more detail information about the i-7531, please visit
our website as follow:
http://www.icpdas.com/products/Remote_IO/can_bus/i-7531.htm

i-7531 CAN Repeater User Manual (ver. 1.2, 2008/02/13) ------4
1.1 Features
High speed
Removable terminal block
Mountable on DIN Rail
Bus pins protected against transients in an industrial environment
No disturbance of the bus lines with an un-powered node
Transmit data (TxD) dominant time-out function prevents the output
drivers from driving a permanent dominant state
A thermal protection circuit is integrated to prevent the transceiver
from damage if the junction temperature exceeds thermal shutdown
level.
1.2 Specifications
Support CAN 2.0A/CAN 2.0B
Fully compatible with ISO 11898-2
Communication baud range: 10Kbps ~ 1Mbps
Propagation Delay: ~200ns
Driving capability: Up to 100 nodes on each CAN port
Photo-coupler isolation between 2 CAN ports: 2500 Vrms
Power consumption: 2W max
CAN terminal resistors are integrated (can be disabled by jumper)
3KV galvanic isolated among of power supply and each CAN port
Power Supply: +10VDC ~ +30VDC
Operating temperature: -25°C ~ +75°C
Humidity: 5% ~ 95%
Dimensions: 123 mm x 72 mm x 33 mm
1.3 Application
Factory Automation
Building Automation
Home Automation
Vehicle Automation
Control system
Monitor system
…

i-7531 CAN Repeater User Manual (ver. 1.2, 2008/02/13) ------5
2 Technical data
2.1 Block Diagram
Figure 2 is a block diagram illustrating the functions of the i-7531 module.
Power supply are with 3000V galvanic isolated between each CAN port.
Futhermore, there is photo-isolation 2500 Vrms between two CAN ports.
2500 Vrms
Photo Isolation
DC
DC
3000V
Isolation
DC
DC
3000V
Isolation
+ 0VDC ~ +30VDC
Block Diagram of I-7531
CAN_L
20 Ohm
CAN_H
CAN_H
CAN_L
20 Ohm
Physical CAN layer
Physical CAN layer
CAN Port
CAN Port 2
Figure2. Block Diagram of i-7531

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2.2 Appearance
Figure3. Apperance of i-7531
Power InputCAN Port 1
CAN Port 2
Status LED of Power
& Communication i-7531
CAN bus Repeater
‧Support CAN 2.0A/2.0B
‧Photo-isolation: 2500 Vrms
‧Expand the num er of CAN uses
‧Mounta le on DIN Rail
3000V Isolation
GND
11
(CAN)
20 CAN_L
CAN_H
FG
GND
10
(CAN)
1
CAN_L
CAN_H
FG
(R)VS+
(B)GND

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2.3 Pin Assignment
GND
(CAN)
20 CAN_L
CAN_H
FG
GND
0
(CAN)
CAN_L
CAN_H
FG
(R)VS+
(B)GND
Figure4. Pin Aassignment of i-7531
Table1. Pin Description of i-7531
No.
Part Name Description
1 CAN_L
CAN_Low. Signal Line of CAN port 1.
3 CAN_H
CAN_High. Signal Line of CAN port 1.
5 GND CAN_Ground (or CAN_GND), Voltage level of
ground of CAN_L and CAN_H of CAN port 1.
7
CAN
Port 1
FG Frame Groud (or CAN_Shield) of CAN port 1.
9 (R)VS+
Voltage Source. It could be +10VDC ~ +30VDC.
10 Power
Input (B)GND
Power Ground.
14 CAN_L
CAN_Low. Signal Line of CAN port 2.
16 CAN_H
CAN_High. Signal Line of CAN port 2.
18 GND CAN_Ground (or CAN_GND), Voltage level of
ground of CAN_L and CAN_H of CAN port 2.
20
CAN
Port 2
FG Frame Groud (or CAN_Shield) of CAN port 2.

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Note 1:
In some cases, the voltage level of CAN_GND of different CAN
device in the same CAN bus system are not equal. At this time, it
could cause some problems to derogate system staibility of this
CAN bus system.
There is one way to relieve this situation; user can connect the
CAN_GND between those CAN devices to achieve equal
voltage level of CAN_GND.
Wiring of CAN_GND is not necessary; user can modify the
configuration of wiring according to actual applications.
Note 2:
If user choices some kinds of signal cable with shield (e.g. STP
Shielded Twisted Pair), then user can use the shield of this cable
to connect FG (CAN_Shield) among different devices in the
same CAN bus system.
FG (CAN_Shield) is used to shield the signal cable, to avoid RF
radiation or other interference.
Wiring of FG is not necessary; user can modify the configuration
of wiring according to actual applications.

i-7531 CAN Repeater User Manual (ver. 1.2, 2008/02/13) ------9
2.4 Wire Connection
CAN DEVICE CAN_H
CAN_L
Power GND
+ 0VDC ~ +30VDC
CAN Bus 2
CAN Bus
CAN_H
CAN_L
CAN_GND
3
CAN_GND
FG (CAN_Shield)
5
6
9
FG (CAN_Shield)
Power
Figure5. Wire Connection of i-7531

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2.5 Status LED
When user turn the i-7531, the status LED of i-7531 will be display with
red light. Moreover, when a message passes through i-7531, the status LED
will be twinkle once with yellow light while the red light is still on.
Note 3:
Twinkling rate correlates with baud rate of CAN bus. User may see
no twinkling when the twinkling period is too short because of the
higher baud rate of CAN bus. Besides, the yellow LED could look
like always on when bus loading is heavy.
2.6 Terminator Resistor Setting
According to the ISO 11898-2 specifications, the CAN bus network must
be terminated by resistor for proper operation. The equivalent resistance
between CAN_H and CAN_L shoue be 60Ω. There are some examples below.
CAN_H
Case : RT= 20Ω
RTRT
CAN_L
Case2: RT= 80Ω
RT
CAN_H
RT
CAN_L
CAN_H
RTRT
CAN_L
Case3: RT= 240Ω
RT
RT
RT
Figure6. Terminator Resistor

i-7531 CAN Repeater User Manual (ver. 1.2, 2008/02/13) ------11
On the other hand, the i-7531 module include two build-in 120Ωterminator
resistors, user can decide to enable those two terminator resistors or not.
The JP2 of i-7531 is used for adjusting terminal resistor on CAN Port 1,
and the JP3 of i-7531 is used for adjusting terminal resistor on CAN Port 2.
Before adjusting JP2 or JP3 of i-7531, user needs to open the cover of
i-7531 first. Those locations of JP2 and JP3 are shown as following:
Figure7. JP2 and JP3 positions
The following connection statuses present the condition if the terminal
resistor is enabled (default) or disabled.
Disable
(Deactivate)
Enable
(Activate)
Figure8. Adjustment of Terminator Resistor

i-7531 CAN Repeater User Manual (ver. 1.2, 2008/02/13) ------12
2.7 Cable Selection
The CAN bus is a balanced (differential) 2-wire interface running over
either a Shielded Twisted Pair (STP), Un-shielded Twisted Pair (UTP), or
Ribbon cable.
The table below show recommended DC parameters of CAN bus line.
Table2. Recommended DC parameters for CAN Bus Line
Wire Cross-Section [mm2]
Resistance [mΩ/m]
~0.25(AWG23) < 90
~0.5 (AWG20) < 50
~0.8 (AWG18) < 33
~1.3 (AWG16) < 20
The recommended AC parameters of CAN bus line are 120Ωimpedance
and 5 ns/m specific line delay.

i-7531 CAN Repeater User Manual (ver. 1.2, 2008/02/13) ------13
2.8 Driving Capability and Baud
The relationship between ideal total bus length and baud are displayed
below. Table3. Baud, Total Bus Length, and Number of i-7531
Baud [bit/sec]
Ideal Bus Length without i-7531 [m]
Max i-7531 Number
1M 25 1
800K 50 1
500K 100 2
250K 250 6
125K 500 12
50K 1000 25
20K 2500 62
10K 5000 125
Note 4:
When users add one i-7531 into a CAN network, the ideal total bus
length will reduce 40 meters because of the propagation delay of
i-7531. For example, if users use baud 500K and one i-7531, the
ideal total bus length will be “100 – 40 * 1 = 60 meters“. Specially, in
baud 1M bps, add one i-7531 will cause the ideal total bus length to
be less than 4 meters.
After deciding the number of i-7531 and calculating the corresponding
ideal bus length, users can use the following table to know the maximum node
number in each segment and the maximum segment length when using
different type of wire. Table4. Driving Capability
The maximum segment length [m] under the
case of specific node number in this segment
Wire Cross-
Section [mm2] 32 Nodes 64 Nodes 100 Nodes
~0.25(AWG23) <200 m <170 m <150 m
~0.5 (AWG20) <360 m <310 m <270 m
~0.8 (AWG18) <550 m <470 m <410 m
~1.3 (AWG16) <900 m <780 m <670 m

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Note 5:
The definition of segment and the relationship between segment
length (Lseg1, Lseg2 …) and ideal total bus length (Ltotal) are shown in
the following figure.
i-753 i-753
L
L2a
L3
L2b
L4
i-753
Segment Segment 2 Segment 3
Segment 4
Lseg = L
Lseg2 = L2a + L2b
Lseg3 = L3
Lseg4 = L4
Ltotal = Lseg + Lseg2 + Lseg3 + Lseg4
Figure9. Definition of Lseg1 and Ltotal

i-7531 CAN Repeater User Manual (ver. 1.2, 2008/02/13) ------15
3 Application Architecture
Backbone of CAN bus
CAN branch
i-753
i-753
Extended
CAN bus
Extended
CAN bus
Electronic isolation
i-753
Backbone use
Extended use
i-753 i-753
Electronic isolation
CAN branch CAN branch
Original
CAN bus
Figure10. Application Architecture

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4 Dimension and Mounting
Figure11. Dimension

i-7531 CAN Repeater User Manual (ver. 1.2, 2008/02/13) ------17
Figure12. Mounting