National Instruments NI 9852 User manual

OPERATING INSTRUCTIONS
NI 9852
2-Port, Low-Speed/Fault-Tolerant CAN Module

NI 9852 Operating Instructions 2 ni.com
These operating instructions describe how to use the National
Instruments (NI) 9852 module. For information about installing,
configuring, and programming your system, refer to your system
documentation. The NI 9852 module requires the NI 985xsoftware
(version 1.2 or higher) to be installed. The latest version of the
NI 985xsoftware is located at ni.com/downloads.
Note The safety guidelines and specifications in this
document are specific to the NI 9852. 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 9852 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 9852 Operating Instructions
Safety Guidelines for Hazardous Locations
The NI 9852 is suitable for use in Class I, Division 2, Groups A, B,
C, D, and T4 hazardous locations; Class 1, 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 9852 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 9852 Operating Instructions 4 ni.com
Caution For Zone 2 applications, install a protection
device between the CAN signals and the NI 9852 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
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 9852
The NI 9852 has two 9-pin male D-Sub connectors that provide
connections to a CAN bus. Each port on the NI 9852 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.

© National Instruments Corp. 5 NI 9852 Operating Instructions
Each port has two isolated 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. Connect the CAN bus
reference ground (sometimes referred to as CAN_V–) to the COM
pin. 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.
Both of the ports on the NI 9852 require an external power supply
of +8 V to +36 V to operate. Supply power from the CAN bus to
the VSUP0 pin on CAN0, and the VSUP1 pin on CAN1.
Pinouts for CAN0 and CAN1 of the NI 9852 are listed in Table 1
and Table 2.

NI 9852 Operating Instructions 6 ni.com
Table 1. Pin Assignments for CAN0
Connector Pin Signal
1No Connection (NC)
2CAN_L
3COM0
4NC
5SHLD
6COM0
7CAN_H
8NC
9 VSUP0
6
7
8
9
1
2
3
4
5

© National Instruments Corp. 7 NI 9852 Operating Instructions
Table 2. Pin Assignments for CAN1
Connector Pin Signal
1No Connection (NC)
2CAN_L
3COM1
4NC
5SHLD
6COM1
7CAN_H
8NC
9 VSUP1
6
7
8
9
1
2
3
4
5

NI 9852 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. Every device on a low-speed/fault-tolerant CAN
network requires a termination resistor for each CAN data line:
RRTH for CAN_H and RRTL for CAN_L.
Figure 1 shows a simplified diagram of a low-speed/fault-tolerant
CAN bus with termination resistor placements.

© National Instruments Corp. 9 NI 9852 Operating Instructions
Figure 1. CAN Bus Topology and Termination Resistor Locations
Connecting a CAN Bus to the NI 9852
Each port of the NI 9852 can be connected to any location on a
CAN bus. Figure 2 shows one example of the connection of CAN0
of the NI 9852 directly to one CAN node, and CAN1 directly to
another CAN node. CAN0 and CAN1 require an external power
supply on the CAN bus.
RTL CAN_L RTH CAN_H RTL CAN_L RTH CAN_H RTL CAN_L RTH CAN_H
CAN_H
CAN_L
Low-speed/Fault-Tolerant
CAN Device
Low-speed/Fault-Tolerant
CAN Device
Low-speed/Fault-Tolerant
CAN Device

NI 9852 Operating Instructions 10 ni.com
Figure 2. Connecting Both Ports of the NI 9852 to CAN Buses
CAN1
CAN Device
CAN0
NI 9852
CAN
Cable
(With
Optional
Shield)
(SHLD)
CAN_H
CAN_L
Vsup1
COM1
(SHLD)
CAN_H
CAN_L
Vsup1
COM1
CAN Device
CAN
Cable
(With
Optional
Shield)
(SHLD)
CAN_H
CAN_L
Vsup0
COM0
(SHLD)
CAN_H
CAN_L
Vsup0
COM0
+
–
External
Power
Supply
+
–
External
Power
Supply

© National Instruments Corp. 11 NI 9852 Operating Instructions
Cabling Requirements for NI 9852
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. Specifications for Characteristics of a CAN_H and CAN_L Pair of
Wires
Characteristic Value
Length-related resistance 90 mΩ/m nominal
Length-related
capacitance:
CAN_L and ground,
CAN_H and ground,
CAN_L and CAN_H
30 pF/m nominal

NI 9852 Operating Instructions 12 ni.com
Determining the Necessary Termination Resistance
for the Board
Unlike High-Speed CAN, Low-Speed/Fault-Tolerant CAN
requires termination at the Low-Speed/Fault-Tolerant CAN
transceiver instead of on the cable itself. Termination requires
two resistors, RTH for CAN_H and RTL for CAN_L. This
configuration allows the Philips Fault-Tolerant CAN transceiver to
detect and recover from bus faults. It is important to determine the
overall termination of the existing network, or the termination of
the individual device, before connecting it to a
Low-Speed/Fault-Tolerant port. Philips recommends an overall
RTH and RTL termination of 100 to 500 Ω(each) for a properly
terminated low-speed network.
Termination on the low-speed/fault-tolerant ports of the NI 9852 is
set through the NI 985xsoftware to either 1 kΩor 5 kΩ.

© National Instruments Corp. 13 NI 9852 Operating Instructions
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 Low-Speed/Fault-Tolerant CAN, up to
32 nodes may be connected to the bus.
NI 9852 Hardware Overview
The NI 9852 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 9852 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 TJA1054A
Low-Speed/Fault-Tolerant CAN that is fully compatible with the
ISO 11898 standard and supports baud rates up to 125 Kbps.

NI 9852 Operating Instructions 14 ni.com
Figure 3. NI 9852 Hardware Overview
+
_
+
_
V
SUP0
Ext Pwr
Supply 0
COM0
CAN_H
CAN_L
Ext Pwr
Supply 1
V
SUP1
COM1
CAN_H
CAN_L
CAN0
CAN1
CAN
Transceiver
+5 V
Reg
CAN
Transceiver
+5 V
Reg
Rx Rx
Rx Rx
Tx Tx
Tx Tx
CAN
Controller
CAN
Controller

© National Instruments Corp. 15 NI 9852 Operating Instructions
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 9852
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.

NI 9852 Operating Instructions 16 ni.com
Specifications
The following specifications are typical for the range –40 to 70 °C
unless otherwise noted.
Low-Speed/Fault-Tolerant CAN Characteristics
Transceiver........................................ Philips TJA1054A
Max baud rate ................................... 125 Kbps
CAN_H, CAN_L bus lines
voltage............................................... –27 to +40 VDC
Supply voltage range (VSUP0/VSUP1 )
CAN0 ......................................... +8 to +36 VDC
CAN1 ......................................... +8 to +36 VDC
RRTH............................................ 1.11 kΩ± 0.5% or
4.99 kΩ± 0.5%
RRTL ............................................ 1.11 kΩ± 0.5% or
4.99 kΩ± 0.5%
MTBF ............................................... 1,052,836 hours at 25 °C;
Bellcore Issue 6, Method 1,
Case 3, Limited Part Stress
Method

© National Instruments Corp. 17 NI 9852 Operating Instructions
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......................... 400 mW max
Receiving ............................. 400 mW max
Sleep mode ................................. 25 μW max
Thermal dissipation (at 70 °C)
Active mode ............................... 1.5 W max
Sleep mode ................................. 1.2 W max
Physical Characteristics
If you need to clean the module, wipe it with a dry towel.
Weight............................................... Approx. 144 g (5.0 oz)

NI 9852 Operating Instructions 18 ni.com
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.

© National Instruments Corp. 19 NI 9852 Operating Instructions
Isolation Voltages
Port-to-port
Withstand.................................... 500 Vrms, 5 s
Continuous ................................. 60 VDC,
Measurement Category I
Port-to-earth ground
Withstand.................................... 500 Vrms, 5 s
Continuous ................................. 60 VDC,
Measurement Category I
Safety Standards
The NI 9852 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
Note For UL and other safety certifications, refer to the
product label, or visit ni.com/certification, search
by model number or product line, and click the
appropriate link in the Certification column.

NI 9852 Operating Instructions 20 ni.com
Hazardous Locations
U.S. (UL) .......................................... Class I, Division 2,
Groups A, B, C, D, T4;
Class I, Zone 2, AEx nA
II T4
Canada (C-UL) ................................. Class I, Division 2,
Groups A, B, C, D, T4;
Class I, Zone 2, Ex nA
II T4
Europe (DEMKO)............................. EEx nA II T4
Environmental
CompactRIO modules are intended for indoor use only. For
outdoor use, mount the CompactRIO system in a suitably rated
enclosure. Refer to the installation instructions for the chassis you
are using for more information about meeting these specifications.
Operating temperature ...................... –40 to 70 °C
Storage temperature .......................... –40 to 85 °C
Ingress protection.............................. IP 40
Operating humidity........................... 10 to 90% RH,
noncondensing