National Instruments 9853 User manual

NI-9853

GETTING STARTED GUIDE
NI 9853
2-Port, High-Speed CAN Module
Français Deutsch 日本語 한국어 简体中文
ni.com/manuals
This document explains how to connect to the NI 9853.

The NI 9853 module requires the latest NI 985x software to be
installed. The latest version of the NI 985x software is at ni.com/
downloads.
Note Before you begin, complete the software and
hardware installation procedures in your chassis
documentation.
Note The guidelines in this document are specific to
the NI 9853. The other components in the system might
not meet the same safety ratings. Refer to the
documentation for each component in the system to
determine the safety and EMC ratings for the entire
system.
Safety Guidelines
Operate the NI 9853 only as described in this document.
Hot Surface This icon denotes that the component
may be hot. Touching this component may result in
bodily injury.
2| ni.com | NI 9853 Getting Started Guide

Caution Do not operate the NI 9853 in a manner not
specified in this document. Product misuse can result in
a hazard. You can compromise the safety protection
built into the product if the product is damaged in any
way. If the product is damaged, return it to NI for
repair.
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 IIC T4
and Ex nA IIC 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.
NI 9853 Getting Started Guide | © National Instruments | 3

Caution Substitution of components may impair
suitability for Class I, Division 2.
Caution For Division 2 and Zone 2 applications,
install the system in an enclosure rated to at least IP54
as defined by IEC/EN 60079-15.
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 Hazardous Locations Use in
Europe and Internationally
The NI 9853 has been evaluated as Ex nA IIC T4 Gc equipment
under DEMKO Certificate No. 03 ATEX 0324020X and is
IECEx 14.0089X certified. Each NI 9853 is marked II 3G and
is suitable for use in Zone 2 hazardous locations, in ambient
temperatures of -40 °C ≤ Ta ≤ -70 °C . If you are using the
NI 9853 in Gas Group IIC hazardous locations, you must use the
device in an NI chassis that has been evaluated as Ex nC IIC T4,
Ex IIC T4, Ex nA IIC T4, or Ex nL IIC T4 equipment.
4| ni.com | NI 9853 Getting Started Guide

Caution You must make sure that transient
disturbances do not exceed 140% of the rated voltage.
Caution The system shall only be used in an area of
not more than Pollution Degree 2, as defined in
IEC 60664-1.
Caution The system shall be mounted in an
ATEX/IECEx-certified enclosure with a minimum
ingress protection rating of at least IP54 as defined in
IEC/EN 60079-15.
Caution The enclosure must have a door or cover
accessible only by the use of a tool.
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.
Connect these signals using twisted-pair cable.
Each port has two common pins (COM) that are internally
connected to the module’s isolated reference and serve as the
NI 9853 Getting Started Guide | © National Instruments | 5

reference ground for CAN_H and CAN_L. You can connect the
CAN bus reference ground (sometimes referred to as CAN_V-) to
one or both COM pins. The port also has an optional shield pin,
SHLD, that you can connect 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
Tables 1 and 2.
Table 4 lists recommended termination resistor values.
6| ni.com | NI 9853 Getting Started Guide

Table 1. Pin Assignments for CAN0
Connector Pin Signal
6
7
8
9
1
2
3
4
5
1 No Connection (NC)
2 CAN_L
3 COM
4 NC
5 SHLD
6 COM
7 CAN_H
8 NC
9 NC
NI 9853 Getting Started Guide | © National Instruments | 7

Table 2. Pin Assignments for CAN1
Connector Pin Signal
6
7
8
9
1
2
3
4
5
1 No Connection (NC)
2 CAN_L
3 COM
4 NC
5 SHLD
6 COM
7 CAN_H
8 NC
9 VSUP
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
8| ni.com | NI 9853 Getting Started Guide

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 two nodes at the far 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.
NI 9853 Getting Started Guide | © National Instruments | 9

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
Connecting a CAN Bus to the NI 9853
You can connect each port of the NI 9853 to any location on a
CAN bus. Figure 2 shows one example of connecting CAN0 of
the NI 9853 directly to one CAN node, and CAN1 directly to
10 | ni.com | NI 9853 Getting Started Guide

another CAN node. CAN1 requires an external power supply on
the CAN bus.
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 Getting Started Guide | © National Instruments | 11

Cabling Requirements for the NI 9853
Cable Specifications
Cables should meet the physical medium requirements specified
in ISO 11898, shown in the following table. Belden cable
(3084A) meets all these 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 Value
Impedance 95 Ω min,
120 Ω nominal,
140 Ω max
Length-related resistance 70 mΩ/m nominal
Specific line delay 5 ns/m nominal
12 | ni.com | NI 9853 Getting Started Guide

Termination Resistors
The termination resistors (Rt) should match the nominal
impedance of the CAN cable and therefore comply with the
values in the following table.
Table 4. Termination Resistor Specification
Characteristic Value Condition
Termination resistor, Rt100 Ω min, Minimum power dissipation:
220 mW
120 Ω nominal,
130 Ω max
Cable Lengths
The cabling characteristics and desired bit transmission rates
affect the allowable cable length. You can find detailed cable
length recommendations 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
NI 9853 Getting Started Guide | © National Instruments | 13

specification says that significantly longer cable lengths may be
allowed at lower bit rates, but you should analyze each node for
signal integrity problems.
Number of CAN Nodes
The maximum number of nodes depends on the electrical
characteristics of the nodes on the network. If all nodes meet the
ISO 11898 requirements, you can connect at least 30 nodes to the
bus. You can connect higher numbers of nodes if the nodes’
electrical characteristics do not degrade signal quality below
ISO 11898 signal level specifications.
The NI 9853 electrical characteristics 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 or the NI 9853 has a Philips SJA1000
controller that is CAN 2.0B-compatible and fully supports both
11-bit and 29-bit identifiers. The port also has a Philips TJA 1041
14 | ni.com | NI 9853 Getting Started Guide

High-Speed CAN transceiver that is fully compatible with the
ISO 11898 standard and supports baud rates up to 1 Mbps.
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 Getting Started Guide | © National Instruments | 15

NI 9853 Specifications
The following specifications are typical for the range -40 °C to
70 °C unless otherwise noted.
High-Speed CAN Characteristics
...........................................................Transceiver Philips TJA 1041
...........................................................Max baud rate 1 Mbps
...........................................................CAN_H, CAN_L bus
lines voltage
-27 to +40 VDC
Supply voltage range (VSUP)
...................................................CAN1 +9 to +30 VDC
...................................................
CAN0 N/A
...........................................................MTBF 1,816,913 hours at 25 °C;
Bellcore Issue 6, Method 1,
Case 3, Limited Part Stress
Method
16 | ni.com | NI 9853 Getting Started Guide

Note Contact NI for Bellcore MTBF specifications at
other temperatures or for MIL-HDBK-217F
specifications.
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
To clean the module, wipe it with a dry towel.
...........................................................
Weight Approx. 144 g (5.0 oz)
NI 9853 Getting Started Guide | © National Instruments | 17

Safety
Connect only voltages that are within the following limits:
Maximum Voltage1
...................................................
Port-to-COM -27 to +40 VDC max,
Measurement Category I
Isolation
Port-to-port
...........................................Continuous 60 VDC,
Measurement Category I up
to 5,000 m altitude
...........................................Withstand 500 Vrms, verified by a 5 s
dielectric withstand test
1The maximum voltage that can be applied or output between any port or VSUP
terminal and a COM terminal without creating a safety hazard.
18 | ni.com | NI 9853 Getting Started Guide

Port-to-earth ground
...........................................Continuous 60 VDC,
Measurement Category I up
to 5,000 m altitude
...........................................Withstand 500 Vrms, verified by a 5 s
dielectric withstand test
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.
Note Do not connect the NI 9853 to signals or use for
measurements within Measurement Categories II, III,
or IV.
NI 9853 Getting Started Guide | © National Instruments | 19