Controller Area Network (Can); Can System Design; Specifications For Terminating Resistor; Notes On Can Bus Installation - Danfoss PLUS+1 MC0XX-1 series Technical Information

Technical Information
PLUS+1® MC0XX-1XX Controller Family

Controller Area Network (CAN)

CAN system design

Specifications for terminating resistor

Specifications
Description
Resistance
Inductance

Notes on CAN Bus installation

Expansion module CAN Bus loading

18 | © Danfoss | April 2018
All PLUS+1 ® modules have CAN ports that conform to CAN 2.0B specifications, including CAN shield.
CAN1 port and CAN2 port on MC050-155/15B controllers cannot be used to download PLUS+1
application programs.
Each end of the main backbone of the CAN bus must be terminated with an appropriate resistance to
provide correct termination of the CAN_H and CAN_L conductors. This termination resistance should be
connected between the CAN_H and CAN_L conductors.
Units Minimum
Ω 110
µH
Total bus impedance should be 60 Ω.
The CAN transceiver will be damaged by any voltage outside of allowable range, (-27 to +36 Vdc), even
with a very short pulse.
If using shielded cable, the shield must be grounded to the machine ground at one point only; preferably
at the mid-point of the CAN bus. Each PLUS+1
shield.
System designers incorporating PLUS+1
PLUS+1 ® CAN bus loading and controller memory usage during system design. Each expansion module is
associated with a PLUS+1 ® controller and uses part of the controller's memory resources for inter-module
communications. The following table can be used to estimate system CAN bus loading and the memory
impact of I/O modules on their associated controller.
Estimated usage of memory and communication resources
Description IX012-010
Estimated
4%
module bus
load (using
default update
and 250K bus
speed)
Estimated 2%
module bus
load (using 70
ms updates
and 250K bus
speed)
RAM usage on
9%
MC012-XXX
RAM usage on
9%
MC024-010
Maximum Nominal
130 120
1
® module CAN shield pin must be connected to the cable
® expansion modules in their applications should be aware of
IX024-010 OX012-010
10% 11%
5% 3%
12% 9%
12% 9%
Comment
Minimum power dissipation 400 mW
(assumes a short of 16 Vdc to CAN_H).
OX024-010 IOX012-010
27% 11%
8% 4%
14% 9%
14% 9%
L1321895 | BC00000227en-US0401
® GUIDE
IOX024-20
27%
8%
17%
17%