ICP DAS USA I-7531-FD User manual

I-7531-FD CAN Repeater User Manual (ver. 1.0, 2021/10/21) ------1
User Manual
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year from the date of delivery to the original purchaser.
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Copyright 2021 by ICP DAS. All rights are reserved.
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The I-7531-FD CAN Repeater

I-7531-FD CAN Repeater User Manual (ver. 1.0, 2021/10/21) ------2
Tables of Content
Tables of Content...........................................................................................2
1Introduction.............................................................................................3
1.1 Features..........................................................................................4
1.2 Specifications ................................................................................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......................................................................................9
2.6 Terminator Resistor Setting........................................................10
2.7Baud rate and wire length of CAN bus.......................................12
3Dimension .............................................................................................14

I-7531-FD CAN Repeater User Manual (ver. 1.0, 2021/10/21) ------3
1 Introduction
The I-7531-FD is a CAN/CAN FD signal repeater, which can connect two
or more CAN networks with the same baud rate. Based on the signal repeat
function of I-7531-FD, users can use differentnumbers of I-7531-FD to combine
tree-shaped and star-shaped CAN network topology, and when there are too
many devices on the CAN network, using I-7531-FD can increase the driving
force of the CAN signal to drive more CAN devices. In addition, the CAN side
of the I-7531-FD has a digital isolation of 2500 Vrms, and the CAN side and the
power side also provide 3000 V DC-DC isolation protection, which can
effectively isolate the noise interference between CAN networks ,and achieve
protection the purpose of a specific CAN network.
Figure1. Application

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1.1 Features
Supported CAN specification 2.0A/B and CAN FD
Fully compatible with the ISO 11898-2 standard
Detected CAN bus baud rate automatically, maximum support 8000
kbps
1.2 Specifications
CAN
Ports
2
Baud Rate
CAN bus: 5 k ~ 800 kbps
CAN FD: Arbitration rate up to 1000 kbps,
data rate up to 8000 kbps
(Note) The data rates are verified by tests, but
user-defined baud rates are possible, so the
maximum data rate will depend on the
concrete operating conditions (cable length,
remote stations, etc.).
Isolation
2500 Vrms for digital isolation, and 3000 V for DC-DC
Terminal Resistor
Build in 120 Ω terminal resistor and support jumper to
select
Specification
ISO-11898-2, CAN 2.0A/B and CAN FD
(CAN FD support ISO and Non-ISO standards)
Time Delay
Typ. 175ns (corresponds to ~35m CAN bus length)
Power
Input Range
+10 VDC ~ +30 VDC
Consumption
1 W
Mechanical
Casing
Plastic

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Mechanical
Dimensions (mm)
72 x 118 x 33 (W x L x H)
Installation
DIN-Rail
Environmental
Operating Temperature
-25 ~ +75 °C
Storage Temperature
-30 ~ +80 °C
Humidity
10 ~ 90% RH, Non-condensing
2 Technical data
2.1 Block Diagram
Figure 2 is a block diagram illustrating the functions of the I-7531-FD
module. Power supply are with 3000 VDC galvanic isolated between each CAN
port. Futhermore, there is digital-isolation 2500 Vrms between two CAN ports.
2500 Vrms
Digital Isolation
DC
DC
3000 VDC
Isolation
DC
DC
3000 VDC
Isolation
+10 VDC ~ +30 VDC
Block Diagram of I-7531-FD
CAN_L
120 Ohm
CAN_H
CAN_H
CAN_L
120 Ohm
Physical CAN layer
Physical CAN layer
CAN Port 1
CAN Port 2
Figure2. Block Diagram

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2.2 Appearance
i-7531
CAN bus Repeater
‧Support CAN / CAN FD
‧Digital-isolation: 2500 Vrms
‧Expand the number of CAN buses
‧Moun table 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
CAN Port 2
Status LED of
Power &
Communication
CAN Port 1 Power Input
Frame Ground
Frame Ground
RUN PWR
Figure3. Apperance

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2.3 Pin Assignment
Figure4. Pin Aassignment
Table1. Pin Description
Pin
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 in CAN port 1.
7
FG
Frame Groud.
9
(R)VS+
Power input +10VDC ~ +30VDC.
10
(B)GND
14
FG
Frame Groud.
16
GND
CAN_Ground (or CAN_GND), Voltage level of ground of CAN_L
and CAN_H in CAN port 2.
18
CAN_H
CAN_High. Signal Line of CAN port 2.
20
CAN_L
CAN_Low. Signal Line of CAN port 2.
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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Note 1:
In normal situation, the CAN_GND does not need to be wired, but
the CAN_GND’s voltage level of different CAN devices are not
equal in some case. When in this situation, it maybe cause some
problems and reduce the stability of the CAN bus system. The
user can connect CAN_GND of these CAN devices to let the
voltage level be same and eliminate this situation.
Note 2:
Electronic circuits are susceptible to electrostatic discharge
(ESD) and will get worse when encountering continental
climates, so F.G. provides a path for ESD to lead to the earth
ground, thereby enhancing the module's ability to protect against
static electricity. If the user wants to use F.G., both pin 7 and pin
14 need to be connected to the earth ground, because the two
pins are not connected inside the module.

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2.4 Wire Connection
CAN DEVICE CAN_H
CAN_L
Power GND
+10VDC ~ +30VDC
CAN_H
CAN_L
CAN_GND
CAN_GND
1
5
6
9
Frame Ground
9-Pin D-sub
Male connector
Frame Ground
Figure5. Wire Connection
2.5 Status LED
LED
Color
Status
Description
1
(PWR)
Red
ON
Power on
OFF
Power off
2
(RUN)
Green
Blink
In communication
OFF
No data in
communication
Note:
RUN LED's 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 LED
could look like always on when bus loading is heavy.
1
2

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2.6 Terminator Resistor Setting
According to the ISO 11898-2 specifications, the bus line of CAN_H and
CAN_L must be terminated by resistor for proper operation. The equivalent
resistance between CAN_H and CAN_L should be 60Ω. There are some
examples below.
Figure6. Terminator Resistor

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On the other hand, the I-7531-FD module has built-in two 120Ω terminating
resistors, and the user can use the jumper to select whether to enableit. Among
them, JP1 is used to adjust the terminal resistance of CAN port 1, and JP2 is
used to adjust the terminal resistance of CAN port 2. If the user wants to adjust
the terminal resistance, who needs to open the casing of I-7531-FD, and will
see the positions of JP1 and JP2 as shown in the figure below:
JP1 JP2
CAN1 CAN2
Figure7. JP1 and JP2 positions
The following connection statuses present the condition if the terminal
resistor is enabled (default) or disabled.
Figure8. Adjustment of Terminator Resistor
Disable
(Deactivate)
Enable
(Activate)

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2.7 Baud rate and wire length of CAN bus
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. However, the baud rate of communication is inversely
proportional to the wire length. When the baud rate is lower, the ideal CAN bus
wire length that can be used is longer, as shown in the following table.
(Note: The ideal CAN bus wire length means the sum of the wire lengths of
each CAN bus in a single CAN network.)
Table2. Baud rate and ideal CAN bus wire lehgth
Baud rate
[bit/sec]
Ideal CAN bus wire length
[meters]
800K
50
500K
100
250K
250
125K
500
50K
1000
20K
2500
10K
5000
In addition, the I-7531-FD can isolate and re-amplify the CAN bus signal,
so the user will think that connecting multiple I-7531-FDs in series on the
same CAN bus, the CAN bus signal will always re-amplify and then extend
the wire length of CAN bus, but the CAN bus signal passing through the I-
7531-FD will reduce the ideal CAN wire length due to the time delay at the
physical layer in fact.
In other words, when the user add one I-7531-FD to the CAN bus, the
CAN signal passing through the I-7531-FD will be delayed by 175ns, and the
ideal CAN bus wire length will be reduced by 35 meters.
For example, the baud rate used by the user is 500Kbps, and the ideal
CAN bus wire length is 100 meters, when one I-7531-FD is connected in
series to the CAN bus, the ideal CAN bus wire length will be reduced by 35
meters that is reduced from 100 meters to 65 meters (100 –35 x 1 = 65).
By analogy, if two I-7531-FDs are connected in series on the CAN bus, it
will reduced by 35 x 2 = 70 meters as shown in the below figure.

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Figure9. Differences after adding I-7531-FD
Therefore, the baud rate and the maximum number of I-7531-FD
supported by a single CAN bus are shown in the following table.
Table3. The number of I-7531-FD supported by a single CAN bus
Baud rate
[bit/sec]
The number of I-7531-FD supported
by a single CAN bus
800K
1
500K
2
250K
7
125K
14
50K
28
20K
71
10K
142
Ideal CAN bus
wire length
Add one
I-7531-FD
Reduce
35m
Isolate, Re-Amplity
CAN bus signal
Reduce
35 x 2 = 70m
Add two
I-7531-FD

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3 Dimension
Figure10. Dimension