Effective: April 2019
Supersedes:
UG-CM0504-1038000-201808-007
CM0504 User Guide
Controller Module
Parker Hannin Canada
Electronic Controls Division
1305 Clarence Avenue
Winnipeg, MB R3T 1T4 Canada
ofce +1 204 452 6776
Fax +1 204 478 1749
http://www.parker.com/ecd
Copyright 2019 © Parker Hannifin Corporation. All rights reserved. No part of this work may be reproduced, published,
or distributed in any form or by any means (electronically, mechanically, photocopying, recording, or otherwise), or stored in
a database retrieval system, without the prior written permission of Parker Hannin Corporation in each instance.
Warning!
FAILURE OR IMPROPER SELECTION OR IMPROPER USE OF THE PRODUCTS AND/OR SYSTEMS DESCRIBED
HEREIN OR RELATED ITEMS CAN CAUSE DEATH, PERSONAL INJURY AND PROPERTY DAMAGE.
• is document and other information from Parker Hannin Corporation, its subsidiaries and
authorized distributors provide product and/or system options for further investigation by users
having technical expertise.
• e user, through its own analysis and testing, is solely responsible for making the nal selection
of the system and components and assuring that all performance, endurance, maintenance,
safety and warning requirements of the application are met. e user must analyze all aspects
of the application, follow applicable industry standards, and follow the information concerning
the product in the current product catalog and in any other materials provided from Parker or its
subsidiaries or authorized distributors.
• To the extent that Parker or its subsidiaries or authorized distributors provide component or
system options based upon data or specications provided by the user, the user is responsible for
determining that such data and specications are suitable and sucient for all applications and
reasonably foreseeable uses of the components or systems.
• e user will be solely responsible for nal disposal of all products.
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CM0504 User Guide
Contents
Publication History ......................................................................................................................... VI
Safety VII
Safety symbols ..................................................................................................................................... VII
General safety regulations .................................................................................................................. VII
Welding after installation ...................................................................................................................VIII
Construction regulations ................................................................................................................... VIII
Safety during installation ...................................................................................................................VIII
Safety during start-up .........................................................................................................................VIII
Safety during maintenance and fault diagnosis ...............................................................................VIII
1. Understanding the CM0504 ............................................................................................ 1
1.1. Diagram conventions ...............................................................................................................2
2. CM0504 Quick start ......................................................................................................... 4
2.1. Gather Required Materials ......................................................................................................4
2.2. Install the Required Software Tools ........................................................................................4
2.2.1. Install the Data Link Adapter Driver Software .......................................................................4
2.2.2. Install the CM0504 Diagnostic Tool ........................................................................................5
2.3. Connect the CM0504 to a System ............................................................................................5
2.4. Congure CM0504 for its application .....................................................................................6
2.5. Include CM0504 slave messaging in your master module ....................................................6
3. Connectors ....................................................................................................................... 7
3.1. Pinouts ......................................................................................................................................8
4. Inputs ..............................................................................................................................10
4.1. Analog input Type 2 ...............................................................................................................10
4.1.1. Analog input Type 2, circuit characteristics .........................................................................10
4.1.2. Analog Inputs Connections ...................................................................................................11
4.2. Power control digital input ....................................................................................................12
4.2.1. Power control input, circuit characteristics .........................................................................12
4.2.2. Power control digital input connections ..............................................................................13
4.3. INPUT2 and INPUT3, alternate functions ............................................................................13
4.3.1. INPUT2 and INPUT3, Frequency or Digital active-low characteristics .............................14
4.3.2. Active-Low Digital Input Connections .................................................................................14
4.4. INPUT4 and INPUT5, alternate functions ............................................................................15
4.4.1. INPUT4 and INPUT5, Resistive characteristics ...................................................................15
4.4.2. INPUT4 and INPUT5, Frequency or Digital active-high characteristics ..............................15
4.4.3. Active-High Digital Input Connections ................................................................................15
4.5. Addressing ..............................................................................................................................16
4.5.1. Addressing installation connections.....................................................................................17
5. Outputs ........................................................................................................................... 18
5.1. High-side outputs ...................................................................................................................18
5.1.1. High-side output capabilities ................................................................................................18
5.1.2. High-Side Output Diagnostics and Fault Detection ............................................................18
5.2. Low-side outputs ....................................................................................................................19
5.2.1. Low-side output capabilities .................................................................................................19
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CM0504 User Guide
5.2.2. Low-Side Output Diagnostics and Fault Detection .............................................................19
5.3. High-Side/Low-Side Output Conguration .........................................................................20
5.3.1. High-Side/Low-Side output connections .............................................................................20
6. Power .............................................................................................................................. 24
6.1. Logic and output power .........................................................................................................24
6.1.1. Logic and output power capabilities .....................................................................................24
6.1.2. Logic and output power connections ...................................................................................24
7. Communication ............................................................................................................. 26
7.1. Controller area network .........................................................................................................26
7.1.1. J1939 CAN Capabilities ..........................................................................................................26
7.1.2. J1939 CAN Installation Connections ....................................................................................26
8. Installation ..................................................................................................................... 28
8.1. Mechanical Requirements .....................................................................................................28
8.2. Dimensions .............................................................................................................................28
8.3. Selecting a Mounting Location ..............................................................................................29
8.4. Mounting the CM0504 to a Vehicle .......................................................................................29
8.5. Designing and Connecting the Vehicle Harness ..................................................................30
9. Environmental Protection ............................................................................................ 31
9.1. General ....................................................................................................................................31
9.2. Environment ...........................................................................................................................31
9.3. Markings/Approvals ...............................................................................................................31
10. Application Examples.................................................................................................... 32
10.1. Implementing Safety Interlocks ............................................................................................32
10.2. Controlling Indicator Lights ..................................................................................................33
10.3. Controlling a Proportional Valve ...........................................................................................33
10.4. Controlling Motor Speed .......................................................................................................34
10.5. Connecting Various Sensors ..................................................................................................35
10.5.1. Open Collector ........................................................................................................................35
10.5.2. Variable Resistance ................................................................................................................36
10.5.3. Variable Reluctance ................................................................................................................37
10.5.4. Switch ......................................................................................................................................38
10.5.5. Voltage .....................................................................................................................................39
10.5.6. CMOS ......................................................................................................................................39
10.5.7. Potentiometer (Ratiometric) .................................................................................................40
10.6. Using one Analog Input as Two Digital Inputs .....................................................................41
11. Software .......................................................................................................................... 42
11.1. CM0504 diagnostic tool .........................................................................................................42
11.1.1. Using the tool ..........................................................................................................................43
11.2. Default J1939 messages ..........................................................................................................57
11.2.1. Conguration summary .........................................................................................................57
11.2.2. J1939 address and identity .....................................................................................................58
11.2.3. Master module J1939 address ...............................................................................................58
11.2.4. Input status message ..............................................................................................................58
11.2.5. Output duty cycle control message .......................................................................................59
11.2.6. Output frequency control message .......................................................................................59
11.2.7. Output status message ...........................................................................................................59
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CM0504 User Guide
Publication History
e following table provides an overview of the changes made to this document over the course of its
publication history.
Release Date Description of Change
Rev. 001 First release of this document
Rev. 002 Pin-outs updated and input characteristics added from HW
desc. 1038F11.00A, 6/24/2016
Rev. 003 Input and output section capabilities updated, other minor
edits per engineering feedback, 1/31/2017
Rev. 004 Associated input names to correct pins and minor edits
throughout per engineering feedback from 7/6/2017
Rev. 005 Edit wire size in connector section. Clarify input types.
Rev. 006 Edits per feedback from HY-JG, 2/12/2018. Software section
and Diagnostic (cong) Tool screen captures added.
Rev. 007 Edit Environmental specs. Fix table size in software section.
Rev. 008 Add Quick Start chapter. Edits to H-Bridge section.
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CM0504 User Guide
Safety
Do not perform the procedures in this manual unless you are experienced in the handling of electronic
equipment.
Contact the manufacturer if there is anything you are not sure about or if you have any questions
regarding the product and its handling or maintenance.
e term “manufacturer” refers to Parker Hannin Corporation.
Safety symbols
e following symbols are used in this document to indicate potentially hazardous situations:
Danger! Risk of death or injury.
Warning! Risk of damage to equipment or degradation of signal
When you see these symbols, follow the instructions carefully and proceed with caution.
General safety regulations
Work on the hydraulics control electronics may only be carried out by trained personnel who are wellacquainted with the control system, the machine, and its safety regulations.
Follow the manufacturer’s regulations when mounting, modifying, repairing, and
maintaining equipment. e manufacturer assumes no responsibility for any accidents
caused by incorrectly mounted or incorrectly maintained equipment. e manufacturer
assumes no responsibility for the system being incorrectly applied, or the system being
programmed in a manner that jeopardizes safety.
Do not use the product if electronic modules, cabling, or connectors
are damaged or if the control system shows error functions.
Electronic control systems in an inappropriate installation and in combination with
strong electromagnetic interference elds can, in extreme cases, cause an unintentional
change of speed of the output function.
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CM0504 User Guide
Welding after installation
Complete as much as possible of the welding work on the chassis before the installation of the system. If
welding has to be done afterwards, proceed as follows:
Do not place the welding unit cables near the electrical wires of the control system.
1. Disconnect the electrical connections between the system and external equipment.
2. Disconnect the negative cable from the battery.
3. Disconnect the positive cable from the battery.
4. Connect the welder’s ground wire as close as possible to the place of the welding.
Construction regulations
e vehicle must be equipped with an emergency stop which disconnects the supply voltage to the
control system’s electrical units. e emergency stop must be easily accessible to the operator. If
possible, the machine must be built so that the supply voltage to the control system’s electrical units is
disconnected when the operator leaves the operator’s station.
Safety during installation
Incorrectly positioned or mounted cabling can be inuenced by radio signals, which can
interfere with the functions of the system.
Safety during start-up
Danger! Risk of death or injury. Do not start the machine’s engine before the control
system is mounted and its electrical functions have been veried.
Do not start the machine if anyone is near the machine.
Safety during maintenance and fault diagnosis
Before performing any work on the hydraulics control electronics, ensure that
• e machine cannot start moving.
• Functions are positioned safely.
• e machine is turned o.
• e hydraulic system is relieved from any pressure.
• Supply voltage to the control electronics is disconnected.
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CM0504 User Guide
1. Understanding the CM0504
e Controller Module (CM) 0504 is a general purpose input / output controller that includes a single
CAN interface, 5 inputs and 4 outputs with error checking. e main function of the module is to
provide a means of controlling high current loads through messages on the CAN bus. e outputs can be
congured as either high-side or low-side drivers. e module outputs can be congured to support up
to two full H-bridge motor drives to control directional motors.
e CM0504 is only available as a CAN slave module and does not support standalone operation.
However, it does support limited congurability, to specify things like input congurations, and update
rates for the messages presented on the CAN bus. e conguration tool is available from our website,
www.parker.com/ecd under ‘Support’.
Figure 1.1. CM0504 controller module
e CM0504 is designed to communicate through a J1939-based Controller Area Network (CAN) and can
be used in any CAN 2.0B application.
e CM0504 has many features, as follows:
• e CM0504 can monitor up to 5 inputs:
• 1 active-high with wake up input (can be used as power control).
• 4 programmable inputs (can be used as analog, digital, resistive, or frequency).
• e CM0504 has 4 outputs:
• up to 25 A load, module total 100 A (can be congured as high-side or
low-side).
• standard 500 Hz PWM default (capable of up to 2 kHz, engineering review required to verify for
each application).
• e CM0504 has 4 connectors (2x Deutsch DTHD 1 position, 1x Deutsch DTP 4 position, 1x Deutsch
DTM 12 position) that are used to interface with the inputs, outputs, power and CAN.
is manual describes the hardware components of the CM0504, but does not explain how to congure
the software. For more information about software, refer to the appropriate software manual or contact
your Parker Vansco Account Representative.
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CM0504 User Guide
1.1. Diagram conventions
e following symbols are used in the schematic diagrams in this document:
Symbol Meaning
General input
General output
Frequency input
Analog input
Frequency sensor
Pulse sensor
Resistive sensor
General sensor
Application switch
Load
Pull-down resistor
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CM0504 User Guide
Symbol Meaning
Pull-up resistor
Battery
Fuse
Resistor
Ground
Chassis ground
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CM0504 User Guide
2. CM0504 Quick start
is section provides step-by-step instructions on how to connect the CM0504, install the required
software tools, and congure the CM0504 software. e following is a high-level overview of the steps
involved with this section:
1. Gather the required materials.
2. Install the required software tools provided by Parker.
3. Connect the CM0504 and power it up.
4. Congure CM0504 for its application. (optional)
5. Include the CM0504 slave messaging into your master module(s).
2.1. Gather Required Materials
e following materials are required for the procedures in this section:
• CM0504
• personal computer (PC)
• harness
• Data Link Adapter (DLA) kit (comes with cables needed for connecting the DLA to your PC and to
the rest of the system)
• power supply compatible with the CM0504 and loads
• software tools and les required for programming and downloading software for the CM0504.
2.2. Install the Required Software Tools
Before using the CM0504, install the following software tools onto your PC:
• Data Link Adaptor (DLA) drivers
• e DLA acts as the interface between the PC and the CM0504. Before using the DLA, you must
install the DLA drivers.
• CM0504 Diagnostic Tool
• Parker provides the CM0504 Diagnostic Tool to download software for the CM0504 and congure its
behavior.
2.2.1. Install the Data Link Adapter Driver Software
A Data Link Adaptor (DLA) is needed when connecting the CM0504 in a development system.
Note: Parker provides the latest DLA software releases through its web site. Please contact your Parker
Account Representative for details on how to download the latest DLA driver software.
e Parker DLA requires the installation of drivers on your PC. To install the Parker DLA drivers:
1. Download the driver, run the extracted le, and follow the Install Wizard. Do not connect the USB
DLA until the driver installation is completed.
2. Connect the USB DLA to a USB port on your PC. e Found New Hardware screen opens.
3. Select Install the software automatically (Recommended), and then click Next. If the driver is not
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CM0504 User Guide
detected automatically, you can browse to the folder containing the driver (default path C:\Program
les\Vansco\USB-DLA).
4. After installation is nished, click Finish. e USB DLA is now recognized and ready to be used.
See the Parker USB DLA kit user manual for more detailed instructions.
2.2.2. Install the CM0504 Diagnostic Tool
e CM0504 Diagnostic Tool is for downloading software for the CM0504 and conguring its behavior.
Note: Please contact your Parker Account Representative for details to obtain and download this
software.
To install:
1. Download the software.
2. Save the EXE le in a known location on your PC.
3. Simply double click the EXE to run (i.e there is no installer).
2.3. Connect the CM0504 to a System
e following shows how to connect the CM0504 to a power supply:
Figure 2.1. CM0504 power connection
Warning! Size fuses for both the Logic Power and High Current Power appropriately.
Improper fusing can result in a re.
Note: By default the CM0504 will wake-up whenever power is applied to pin J1-12 but it may also be
congured to wake on J1-4 or CAN. See sections 3.2.1, 3.2.2, and module settings in 10.1.1 for details.
Important: Both J2 and J4 must always be connected as shown above.
Important: ere are 2 ground reference pins in connector J1 – they must not be connected to the power
supply return.
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CM0504 User Guide
To use the CM0504 diagnostic tool, the PC must be connected to the CM0504 through the Parker USBDLA as shown in the following diagram:
Power
Controller
DLA
PC
Figure 2.2. Connect Parker USB-DLA
2.4. Configure CM0504 for its application
e CM0504 comes with the J1939 slave application preinstalled and a default conguration that may
meet the needs of your application. However, in case the conguration needs to be changed, Parker
provides the CM0504 Diagnostic tool. e tool may be used to congure the following features of the
CM0504:
• Input type (e.g. digital, analog, frequency)
• Output type (e.g. high side, low side, or H-Bridge)
• Wakeup options (e.g. always on, wake on input, or wake on CAN)
• J1939 slave messages used (e.g. PGN, SA, DA, and broadcast rate)
For details, see sections:
• 10.2 -- default conguration
• 10.1 – detailed instructions for the CM0504 Diagnostic tool
2.5. Include CM0504 slave messaging in your master module
e CM0504 is a slave module which requires a master on the J1939 network to process the value of its
inputs and tell it the desired state of its outputs. e J1939 messages used by the CM0504 for this purpose
are described in section 10.2. is document assumes the development environment used for the master
module provide the facilities to construct these 4 J1939 messages as required.
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CM0504 User Guide
3. Connectors
e CM0504 has 1 Deutsch DTM 12 position connection:
• J1: DTM04-12PA
is connector is used to connect to the inputs, and communication channels used by the CM0504. e
required connector is:
Figure 3.1. DTM06-12SA connector
e CM0504 has 1 Deutsch DTP 4 position connection.
• J3: DTP04-4P
is connector is used to connect to the outputs used by the CM0504. e required connector is:
Figure 3.2. J3 connector
e CM0504 also has 2 Deutsch DTHD 1 position connections for power and ground:
• J2: DTHD04-1-4P
• J4: DTHD04-1-4P
e required connector is:
Figure 3.3. J2 & J4 connector
e maximum wire gage for the J2 and J4 connectors is 6 AWG with GXL insulation.
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CM0504 User Guide
e following table shows the part numbers for the mating connectors and terminals that are used in the
vehicle harness.
Connector Shell part no. Wedge part no. Terminal part no.
Gray (J1) connector DTM06-12SA WM12S 16-20 AWG, Gold:
Gray (J3) connector DTP06-4S WP4S 12-14 AWG, Gold:
Black (J2) connector DTHD06-1-4S - 6 AWG:
Black (J4) connector DTHD06-1-4S - 6 AWG:
3.1. Pinouts
Pins connect to inputs, outputs, and communication channels. ey provide the interface between the
vehicle harness and the internal circuitry of the CM0504.
e following tables show the pinouts for each connector:
Pin I/O Name Function
1
2
3
4
5
6
7
8
9
10
11
12
Mating Connector Part Numbers
GND
CAN_L
CAN_SHLD
INPUT5
INPUT1
ADDR_L/GND
ADDR_H/SENSOR
INPUT2
INPUT3
INPUT4
CAN_H
+VBATT
1062-20-0144
1062-12-0144
0462-203-04141
0462-203-04141
J1 Connector Pinout
Ground (logic / sensor ground)
CAN low
CAN shield
General purpose input Type 2
Active high digital wake up input
Address low, IDtag / (sensor ground)
Address high, IDtag / (+5 V supply)
General purpose input Type 1
General purpose input Type 1
General purpose input Type 2
CAN high
Logic power (positive battery terminal)
J2 Connector Pinout
Pin I/O Name Function
1
Pin I/O Name Function
1
2
3
4
8
GND
OUTPUT2_25A
OUTPUT4_25A
OUTPUT3_25A
OUTPUT1_25A
Negative battery terminal (LS output ground)
J3 Connector Pinout
High-side or low-side output, 25 A
High-side or low-side output, 25 A
High-side or low-side output, 25 A
High-side or low-side output, 25 A
CM0504 User Guide
J4 Connector Pinout
Pin I/O Name Function
1
+VBATT
Positive battery terminal (HS output power)
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CM0504 User Guide
4. Inputs
e CM0504 has analog, digital, resistive, and frequency inputs.
e following table shows the input numbers and their possible congurations:
Analog, type 2 X X X X
Resistive, type 1 X X X
Frequency, type 1 X X X X
Frequency, type 2 X X
Digital, type 1
(active low)
Digital, type 2
(active high)
Type Input1 Input2 Input3 Input4 Input5 IDTag (addr)
Wake up X
X X
X X X
Damage to equipment! Do not connect inputs directly to unprotected inductive loads
such as solenoids or relay coils, as these can produce high voltage spikes that may
damage the CM0504. If an inductive load must be connected to an input, use a protective
diode or transorb.
4.1. Analog input Type 2
ere are 4 analog Type 2 inputs (INPUT2, INPUT3, INPUT4, INPUT5).
e primary function of the Analog input Type 2 is to interface 0-5V sensors in an application.
4.1.1. Analog input Type 2, circuit characteristics
e following table provides specications for the analog input:
Analog input Type 2 characteristics
Item Min Nom Max Unit
Input voltage range (non-operational) 0 32 V
Full scale input voltage 0 5 V
Pull-up resistance open
Input resistance w.r.t. ground (pull-up/pulldown inactive)
Resolution 0.81 mV/bit
Offset error 3.2 mV
Gain error 3.2 mV
Non-linearity error 2.4 mV
Filtering hardware cutoff frequency 39.3 Hz
89 kΩ
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CM0504 User Guide
4.1.2. Analog Inputs Connections
Sensor Power
Analog inputs are susceptible to system noise, which can aect the accuracy of the signal. Signal
accuracy can also be aected by ground level shift, which can cause inputs to activate when they
shouldn’t.
System noise
To prevent noise pickup on the sensors,
• Use the shortest possible wires when connecting analog inputs to sensors.
e following shows how to connect an analog input to reduce system noise:
Sensor
Analog Input
Internal to product
Sensor Ground
Figure 4.1. Analog input for system noise reduction
Ground level shift
To reduce ground level shift:
1. Dedicate one of the 2 system ground inputs (GND) to sensors that have dedicated ground wires, and
connect all sensor grounds to this system ground input.
2. Splice the other system ground inputs together in the vehicle harness (close to the connector) to
provide a better ground for the noisier low-side outputs and digital circuits.
3. Position the sensor’s ground connection near the system ground connections to ensure that the
signal remains within the digital activation range of the input.
Note 1: e system ground inputs are rated for low-current signals, which ensures the sensor’s ground is
very close in voltage potential to the system ground.
Note 2: Sensors that don’t have a dedicated ground wire are typically grounded to the vehicle chassis
through the sensor’s body.
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CM0504 User Guide
Sensor Power
Active Sensor
Internal to product
Analog Input
Pull-up
Resistor
Resistive Sensor
Figure 4.2. Analog input ground shift connection for sensors that have dedicated ground wires
Analog Input
4.2. Power control digital input
e CM0504 has 1 active-high power control digital input that is used for waking up (turning on) the
product (INPUT1).
is type of input has a pull-down resistor option only. When the input is active it turns on the power
supply pass transistor to power up the unit. e input is sensed directly by the microprocessor.
4.2.1. Power control input, circuit characteristics
e following table provides specications for the CM0504 power control digital input:
Power control digital input characteristics
Item MIN NOM MAX UNIT
Input voltage range 0 32 V
Over-voltage 36 V
Pull-down resistance 21.2 kΩ
Capacitance at pin 1000 pF
Input Power Up Threshold 2.5 4.3 V
Note: e power control digital input voltage must be greater than 4.3 V before it is considered an active
high input.
e power control digital input wakes up the CM0504 when switched high to a voltage of 4.3 V or greater.
e CM0504 will shut o when an open circuit condition occurs on the power control digital input,
unless it is congured to ‘Wake on CAN’.
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CM0504 User Guide
4.2.2. Power control digital input connections
If the active high digital input is congured to wake up the module:
• e power control digital input is usually connected to the vehicle ignition, but it can be connected
to any power source in a system.
• To protect the harness that connects the CM0504 to the ignition, place a fuse of 200 mA or higher in
the circuit that feeds the CM0504.
• When battery power (VBATT) is connected, and the power control digital input is inactive, the
CM0504 will go into sleep mode.
• e CM0504 has ‘Wake on CAN’ capability. Even when it is not congured for wake on CAN, the bus
must be completely silent in order for the CM0504 to stay in low power sleep mode. Until the correct
wakeup conditions are sensed, the CM0504 will appear “o” (outputs o and no CAN tx) but there is
no way to keep its power supply o if there is CAN activity on the bus.
If your CM0504 must always be powered, the power control digital input does not need to be used. e
CM0504 can be congured to always be powered using the CM0504 Conguration Tool software.
e following diagram shows a typical power control digital input connection:
Internal to product
Application Switch
Power Control Input
Power
Control
Pull-Down
Resistor
Battery
Figure 4.3. Power control digital input installation connections
4.3. INPUT2 and INPUT3, alternate functions
e alternate functions for inputs INPUT2 - INPUT3 is as digital (active-low) inputs and as frequency
(type 1 & type 2) inputs.
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CM0504 User Guide
4.3.1. INPUT2 and INPUT3, Frequency or Digital active-low
characteristics
e following table provides specications for INPUT2 and INPUT3:
Alternate functions input characteristics
Frequency or Digital active-low configuration
Item Min Nom Max Unit
Input voltage range 0 32 V
Input frequency range 100 1500 Hz
Pull-up resistance 5.62 open kΩ
Input resistance w.r.t. ground (pullup/pull-down inactive)
Resolution 1 Hz
Positive threshold 5.0 V
Negative threshold 5.72 V
Filtering low pass cutoff frequency 3656 Hz
89 kΩ
4.3.2. Active-Low Digital Input Connections
An active-low digital input is typically connected to a switch that is either open or closed.
• When the switch is open, the pull-up resistor will ensure no signal exists on the input pin, which will
be interpreted by the CM0504 as inactive.
• When the switch is closed, the input is connected to ground, which will be interpreted by the
CM0504 as active.
e active-low input must be connected to ground to ensure there is a ground connection when the state
of the input changes.
e following shows a typical active low digital input connection:
Internal to product
Application Switch
Active High
Digital Input
Battery
Figure 4.4. Active low digital input connections
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CM0504 User Guide
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