National Instruments NI 9853 User manual

OPERATING INSTRUCTIONS
NI 9853
2-Port, High-Speed CAN Module

NI 9853 Operating Instructions 2 ni.com
These operating instructions describe how to use the National
Instruments (NI) 9853 module. For information about installing,
configuring, and programming your system, refer to your system
documentation. The NI 9853 module requires the NI 9853 software
to be installed. The latest version of the NI 9853 software is located
at ni.com/downloads.
Note The safety guidelines and specifications in this
document are specific to the NI 9853. The other
components in your system may not meet the same safety
ratings and specifications. Refer to the documentation for
each component in your system to determine the safety
ratings and specifications for the entire system.
Safety Guidelines
Operate the NI 9853 only as described in these operating
instructions.
Hot Surface This icon denotes that the component may be
hot. Touching this component may result in bodily injury.

© National Instruments Corp. 3 NI 9853 Operating Instructions
Safety Guidelines for Hazardous Locations
The NI 9853 is suitable for use in Class I, Division 2, Groups A, B,
C, D, T4 hazardous locations; Class I, Zone 2, AEx nA II T4 and
Ex nA II T4 hazardous locations; and nonhazardous locations only.
Follow these guidelines if you are installing the NI 9853 in a
potentially explosive environment. Not following these guidelines
may result in serious injury or death.
Caution Do not disconnect I/O-side wires or connectors
unless power has been switched off or the area is known
to be nonhazardous.
Caution Do not remove modules unless power has been
switched off or the area is known to be nonhazardous.
Caution Substitution of components may impair
suitability for Class I, Division 2.
Caution For Zone 2 applications, install the
CompactRIO system in an enclosure rated to at least
IP 54 as defined by IEC 60529 and EN 60529.

NI 9853 Operating Instructions 4 ni.com
Caution For Zone 2 applications, install a protection
device between the CAN signals and the NI 9853 CAN
pins. The device must prevent the CAN Port-to-COM
voltage from exceeding 55 V if there is a transient
overvoltage condition.
Special Conditions for Safe Use in Europe
This equipment has been evaluated as EEx nA II T4 equipment
under DEMKO Certificate No. 03 ATEX 0324020X. Each module
is marked II 3G and is suitable for use in Zone 2 hazardous
locations.
Wiring the NI 9853
The NI 9853 has two 9-pin male D-Sub connectors that provide
connections to a CAN bus. Each port on the NI 9853 has pins for
CAN_H and CAN_L, to which you connect the CAN bus signals.
These signals should be connected using twisted-pair cable.
Each port has two common pins (COM) that are internally
connected to the isolated reference of the module and serve as the
reference ground for CAN_H and CAN_L. You can connect the
CAN bus reference ground (sometimes referred to as CAN_V–) to

© National Instruments Corp. 5 NI 9853 Operating Instructions
one or both of the COM pins. Each port also has an optional shield
pin, SHLD, that can be connected to a shielded CAN cable.
Connecting SHLD may improve signal integrity and EMC
performance in a noisy environment.
CAN0 of the NI 9853 is internally powered, and therefore requires
no external power supply. CAN1 requires an external power supply
of +8 to +25 V to operate. Supply power to the VSUP pin of CAN1
from the CAN bus.
Note Although CAN0 of the NI 9853 does not require an
external power supply to operate, it can be connected to a
powered CAN bus without being damaged.
Pinouts for CAN0 and CAN1 of the NI 9853 are listed in Table 1
and Table 2.
Table 4 lists recommended termination resistor values.

NI 9853 Operating Instructions 6 ni.com
Table 1. Pin Assignments for CAN0
Connector Pin Signal
1No Connection (NC)
2CAN_L
3COM
4NC
5SHLD
6COM
7CAN_H
8NC
9NC
6
7
8
9
1
2
3
4
5

© National Instruments Corp. 7 NI 9853 Operating Instructions
Table 2. Pin Assignments for CAN1
Connector Pin Signal
1No Connection (NC)
2CAN_L
3COM
4NC
5SHLD
6COM
7CAN_H
8NC
9 VSUP
6
7
8
9
1
2
3
4
5

NI 9853 Operating Instructions 8 ni.com
CAN Bus Topology and Termination
A CAN bus consists of two or more CAN nodes cabled together.
The CAN_H and CAN_L pins of each node are connected to the
main CAN bus cable through a short connection known as a “stub.”
The pair of signal wires, CAN_H and CAN_L constitutes a
transmission line. If the transmission line is not terminated,
each signal change on the bus causes reflections that may cause
communication errors. Because the CAN bus is bidirectional, both
ends of the cable must be terminated. However, this requirement
does not mean that every node on the bus should have a termination
resistor—only the nodes at the end of the cable should have
termination resistors.
Figure 1 shows a simplified diagram of a CAN bus with multiple
CAN nodes, and proper termination resistor (Rt) locations.

© National Instruments Corp. 9 NI 9853 Operating Instructions
Figure 1. CAN Bus Topology and Termination Resistor Locations
CAN
Node
CAN
Node
CAN
Node
RtRt
CAN
Node
CAN_H
CAN_L
CAN_H
CAN_L
CAN_H
CAN_L
CAN_H
CAN_L
Bus Cable Length
Stub
Length

NI 9853 Operating Instructions 10 ni.com
Connecting a CAN Bus to the NI 9853
Each port of the NI 9853 can be connected to any location on a
CAN bus. Figure 2 shows one example of the connection of CAN0
of the NI 9853 directly to one CAN node, and CAN1 directly to
another CAN node. CAN1 requires an external power supply on
the CAN bus.

© National Instruments Corp. 11 NI 9853 Operating Instructions
Figure 2. Connecting Both Ports of the NI 9853 to CAN Buses
CAN1
CAN Device
CAN0
NI 9853
Rt
CAN
Cable
(With
Optional
Shield)
(SHLD)
CAN_H
CAN_L
Vsup
COM
Rt
(SHLD)
CAN_H
CAN_L
Vsup
COM
CAN Device
Rt
CAN
Cable
(With
Optional
Shield)
(SHLD)
CAN_H
CAN_L
Vsup
COM
Rt
(SHLD)
CAN_H
CAN_L
Vsup
COM
+
–
External
Power
Supply

NI 9853 Operating Instructions 12 ni.com
Cabling Requirements for NI 9853
This section deals with cabling specifications, termination
resistors, cable lengths, and the number of CAN nodes that can
exist in a system.
Cable Specifications
Cables should meet the physical medium requirements specified in
ISO 11898, shown in Table 3. Belden cable (3084A) meets all of
those requirements, and should be suitable for most applications.
Table 3. ISO 11898 Specifications for Characteristics of a CAN_H and
CAN_L Pair of Wires
Characteristic Valu e
Impedance 95 Ωminimum, 120 Ωnominal, 140 Ωmaximum
Length-related
resistance
70 mΩ/m nominal
Specific line delay 5 ns/m nominal

© National Instruments Corp. 13 NI 9853 Operating Instructions
Termination Resistors
The termination resistors (Rt) should match the nominal
impedance of the CAN cable, and therefore comply with the values
in Table 4.
Cable Lengths
The allowable cable length is affected by the characteristics of the
cabling and the desired bit transmission rates. Detailed cable length
recommendations can be found in the ISO 11898, CiA DS 102, and
DeviceNet specifications.
ISO 11898 specifies 40 m total cable length with a maximum
stub length of 0.3 m for a bit rate of 1 Mb/s. The ISO 11898
specification says that significantly longer cable lengths may be
allowed at lower bit rates, but each node should be analyzed for
signal integrity problems.
Table 4. Termination Resistor Specification
Characteristic Value Condition
Termination resistor, Rt100 Ω min,
120 Ωnominal,
130 Ωmax
Minimum power
dissipation: 220 mW

NI 9853 Operating Instructions 14 ni.com
Number of CAN Nodes
The maximum number of nodes depends on the electrical
characteristics of the nodes on the network. If all of the nodes meet
the requirements of ISO 11898, at least 30 nodes may be connected
to the bus. Higher numbers of nodes may be connected if the
electrical characteristics of the nodes do not degrade signal quality
below ISO 11898 signal level specifications.
The electrical characteristics of the NI 9853 allow at least
110 CAN ports on a network.
NI 9853 Hardware Overview
The NI 9853 has two full-featured, independent CAN ports that are
isolated from each other, and from the other modules in the system.
Each port of the NI 9853 has a Philips SJA1000 CAN controller
that is CAN 2.0B-compatible and fully supports both 11-bit
and 29-bit identifiers. Each port also has a Philips TJA1041
High-Speed CAN transceiver that is fully compatible with the
ISO 11898 standard and supports baud rates up to 1 Mbps.

© National Instruments Corp. 15 NI 9853 Operating Instructions
Figure 3. NI 9853 Hardware Overview
Rx
Tx
CAN
Transceiver
+5 V_ISO +5 V
GND
COM
CAN_H
CAN_L
+5 V
Reg
Rx
Tx
Ext Pwr
Supply
CAN
Controller
Rx
Tx CAN
Controller
CAN_H
CAN_L
CAN
Transceiver
Rx
Tx
COM
Vsup
CAN0
CAN1
+
_
Iso Pwr

NI 9853 Operating Instructions 16 ni.com
Sleep Mode (CompactRIO Only)
You can enable sleep mode for the CompactRIO system in
software. In sleep mode, the system consumes less power and may
dissipate less heat. Typically, when a system is in sleep mode, you
cannot communicate with the modules. Refer to the Specifications
section for more information about power consumption and
thermal dissipation.
This system sleep mode should not be confused with the NI 9853
Transceiver Mode Sleep property, which sets only the CAN port to
sleep mode. Refer to the FPGA Module topic in LabVIEW Help for
more information on the Transceiver Mode property.

© National Instruments Corp. 17 NI 9853 Operating Instructions
Specifications
The following specifications are typical for the range –40 to 70 °C
unless otherwise noted.
High-Speed CAN Characteristics
Transceiver........................................ Philips TJA1041
Max baud rate ................................... 1 Mbps
CAN_H, CAN_L bus lines
voltage............................................... –27 to +40 VDC
Supply voltage range (VSUP)
CAN0 ......................................... N/A
CAN1 ......................................... +8 to +25 VDC
MTBF ............................................... 1,816,913 hours at 25 °C;
Bellcore Issue 6, Method 1,
Case 3, Limited Part Stress
Method
Note Contact NI for Bellcore MTBF specifications at
other temperatures or for MIL-HDBK-217F
specifications.

NI 9853 Operating Instructions 18 ni.com
Power Requirements
Power consumption from chassis
Active mode
Transmitting ......................... 625 mW max
Receiving ............................. 400 mW max
Sleep mode ................................. 25 μW max
Thermal dissipation (at 70 °C)
Active mode ............................... 1 W max
Sleep mode ................................. 250 mW max
Physical Characteristics
If you need to clean the module, wipe it with a dry towel.
Weight............................................... Approx. 144 g (5.0 oz)

© National Instruments Corp. 19 NI 9853 Operating Instructions
Safety
Maximum Voltage1
Connect only voltages that are within these limits.
Port-to-COM..................................... –27 to +40 VDC max,
Measurement Category I
Measurement Category I is for measurements performed on
circuits not directly connected to the electrical distribution system
referred to as MAINS voltage. MAINS is a hazardous live electrical
supply system that powers equipment. This category is for
measurements of voltages from specially protected secondary
circuits. Such voltage measurements include signal levels, special
equipment, limited-energy parts of equipment, circuits powered by
regulated low-voltage sources, and electronics.
Caution Do not connect to signals or use for
measurements within Measurement Categories II, III,
or IV.
1 The maximum voltage that can be applied or output between any port or VSUP
terminal and a COM terminal without creating a safety hazard.

NI 9853 Operating Instructions 20 ni.com
Isolation Voltages
Port-to-port
Withstand.................................... 500 Vrms, verified by a
dielectric withstand test, 5 s
Continuous ................................. 60 VDC,
Measurement Category I
Port-to-earth ground
Withstand.................................... 500 Vrms, verified by a
dielectric withstand test, 5 s
Continuous ................................. 60 VDC,
Measurement Category I
Safety Standards
The NI 9853 is designed to meet the requirements of the following
standards of safety for electrical equipment for measurement,
control, and laboratory use:
• IEC 61010-1, EN 61010-1
• UL 61010-1, CSA 61010-1