Danfoss CAN User guide

Tech Note

CAN bus components

Introduction

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Introduction		Danfoss has introduced a new remote control		•	Improved performance
		system with CAN bus components that will		•	Lower installation costs
		give customers greater flexibility as far as their		•	Easier servicing
		particular application needs are concerned. In		•	Improved safety
		the new series, focus has been particularly		•	Flexibility
		concentrated on:		CAN components can be used together with
				PVG 32, PVG 120 and PVG 83.
What is CAN bus		The CAN (Controller Area Network) bus was		•	Safety
		originally designed for the automobile industry.		•	Reliability
		It is a serial communication interface in which		•	Real time control
		special emphasis is placed on the following		•	Costs (installation/service)
		parameters:

10-1998

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Book 9 Partition 5

1

CAN communication	CAN communication is best understood in the
	following way:
	Instead of sending a message from compo-
	nent A to unit B, it is broadcast. Each compo-
	nent, a PVG CIP for example, is then able to
	listen in and col-lect information relevant to it
	selv. The message format is designated COB
	(Communication Object), which applies to all
	messages.
	A COB has an identification code (COB-ID)
	that makes it possible for a component, a PVG
	CIP for example, to sort and prioritise trans-
	mitted communication objects (COBs). The
	COB-ID clearly identifies the COB in a network.

CAN communication works on the prioritising of messages, thus CAN uses familiar and established methods such as CSMA/CA (Carrier Sense, Multiple Access with Collision Avoidance) with improved capability to avoid collision (non-destructive bit arbitration). This means that the message with the lowest identification code will have access to the bus before other messages, ensuring that the capacity of the bus can be utilised to the maximum.

The speed of the bus is limited by its length, see below.

Baud rate

Bus length

CANopen	CAN components communicate using a
	protocol. A protocol can be compared to a
	language. The different protocols on the
	market are adapted to the applications in
	which they are used.
	The CANopen protocol is particularly suitable
	for mobile applications. There are many
	suppliers on the market whose products work
	together with CANopen, therefore it is easy to
	put together a comprehensive CANopen
	system.
	CANopen uses objects for communication.
	The most common are:
	Service Data Object(SDO)
	SDOs transfer large amounts of information
	that is not time-critical eg setting-up parame-
	ters.
	Process Data Object (PDO)
	PDOs are used to transfer data that are time-
	critical. For example, joysticks transfer signals
	via PDOs.

NMT is a special part that handles emergency situations and other network administration.

Via an emergency object, the individual nodes (components) are able to send a warning of emergency situations. In this way, other CANopen components are able to identify the node point from which the emergency call was sent.

CANopen specifies an Object Dictionary (OD) that describes all parameters in the product. This OD does not function solely as a specification file, but also as an interface with other CANopen devices. In other words, a description is given detailing which parameters are necessary to activate the different functions the product can perform.

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Prop 1	Prop 2	Prop 3	Prop 4 Prop 1-4 Push 1	Push 2	...Push

	Identifica-	Data field	CRC
Start of frame	tion code	DLC (Data	Receipt field

Length Code)

RTR (Remote

Transmission Request)

The example above shows the structure of a joystick COB.

1.A COB is started by sending a 0 (start of frame).

2.An identification code (COB-ID) is sent and through bit arbitration the message having the lowest bit identification code is allowed to continue.

3.RTR (Remote Transmission Request) specifies whether the sender wishes to receive or send data to the message receiver.

4.DLC specifies the length of the data field.

5.The data field contains information on, for example, joystick data.

6.The CRC field is used as a safety control for finding bit error.

7.The receipt field is a position in which all other components acknowledge receiving a message.

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Danfoss CAN concept CAN components supplied by Danfoss can be identified from the abbreviation CIP (CAN Interfaced Product). We supply the following:

•PVG CIP

•Prof 1 CIP

•CIP Configuration Tool

Our objective is to supply CAN components which are not only capable of communicating with our own products, but also with other

standard available components. There are many suppliers of CANopen components on the market and therefore it is simple, inexpensive and very flexible to set up a comprehensive system.

The CIP Configuration Tool is designed to guide hydraulic system designers/ service technicians through system setup.

Prof 1 CIP	The Prof 1 CIP joystick is available in many
	mechanical configurations. To simplify the way
	in which this information is shown in the COB,
	the maximum configuration possibilities are
	always built in. Depending on the actual confi-
	guration of the joystick, some of the fields for
	proportional or on/off signals contain no infor-
	mation. The joystick sends information on the
	first PDO (Process Data Object). As standard,
	it sends cyclically at Tc = 10 ms.
	The Emergency Object is used if a fault arises
	in the joystick.
	Prof 1 CIP can be ordered as described in
	Tech Note HN.50.Z3 Joystick Prof 1. New
	modules for Prof 1 CIP are shown in the table
	below.

Prof 1 CIP contains new functions often requested in hydraulic systems:

Joystick guide (x - y interlook)

This function ensures that only the first proportional signal activated from the control lever is sent (prop 1 or prop 2).

Memory function

This function makes it possible for the user to hold a proportional function by pressing a selected memory button (on/off) in the joystick. The associated proportional signal can be deactivated by pressing the memory button again or by activating the proportional function in the opposite direction.

	Name	Code no. 162B....	Pos. no. in code no. list	Description
				Length 230 mm with
	Cable	6100	6	AMP 282404-1, male plug
				AMP 282107-1, tab house
	Main function module with	5100	5	CAN electronics
	electronics

PVG CIP	PVG CIP is designed to control up to eight		•	Two different ramps (principle 1 from EH
	sections equipped with PVEO, PVEM, PVEH			boxes)
	or PVES, and versions with float position con-		•	Flow limitation
	trol.		•	Deadband compensation
	PVG CIP is able to receive COBs sent in		•	Gain
	joystick format from four joysticks or other		•	Software tuning of spool characteristics
	sources. The joystick signals are distributed to		•	Spool float position control
	the PVEs in relation to the actual setup. The		•	Power saving
	CAN signals are converted to proportional or		•	Service and diagnosing
	on/off values on the output pins of the module.		•	Softwiring
	PVG CIP contains functions often used in		PVG CIP must be ordered as a separate com-
	hydraulic systems:
			ponent with code number as follows.
	Name	Code no.			Description
		155U....
	PVG CIP	5660			With AMP plug 1-967280-1, male plug

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CIP Configuration Tool The CIP Configuration Tool is a program developed for setting up systems consisting of PVG CIP and Prof 1 CIP.

	Name	Code no.	Description
		155U....
	CIP Configuration Tool	5670	Product contents
			•	CIP Configuration Tool
			•	CIP Downloading Utility
			•	CANview
			•	CAN dongle

• Documentation, examples, help files

Common to PVG CIP & Prof 1 CIP

Technical data

Power supply

Supply voltage	Udc	10	- 30 V DC
Max. supply voltage		36	V DC
Max. pulsation (peak to peak)		5%

CAN interface - ISO 11898 ver. 2.0 B

Baud rate	10 Kbit/s - 1000 Kbit/s
Communication profile	CANopen ver. 3.0
Typical start-up time	< 500 ms
CAN	Full CAN

EMC - EMC Directive (89/336/ECC)

	Emission	EN 50081-2
	Immunity	EN 50082-2
	HF immunity	ISO 14892 (60 V/m, 20 MHz - 1000 MHz)
		ISO 13766 (60 V/m, 20 MHz - 1000 MHz)

Environmental data

Storage temperature		-40°C to +90°C
Ambient temperature
		-30°C to +70°C
Operating temperature

Termination

A CAN bus must be terminated at both ends where CAN+ and CANare to be connected via a 120 Ω resistor.

Termination can be effected by connecting a jumper between the pins given below (a 120 Ω resistor is fitted in the component).

Prof 1 CIP

CAN_TERM	Pin 1
CAN+	Pin 4

PVG CIP

CAN_TERM	Pin 16
CAN+	Pin 3

References

	ISO 11898	Vehicles, interchange of digital information - Controller Area
		Network (CAN) for high-speed communication
		CANopen communication profile for industrial systems, CiA
	CANopen	standard draft 3.0
		Revision 3.0
	EMC Directive	89/336/ECC
	ISO 14892	Agricultural and forestry machines - electromagnetic compatibility
	ISO 13766	Earth-moving machinery - electromagnetic compatibility

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Prof 1 CIP data format The data format is independent of the mechanical configuration. It is manufactured so that a signal for an 8-bit processor can be extracted without signal manipulation. This gives 8- bit signal resolution, and in order to get full

resolution (10 bit) signal manipulation is necessary. This is standard on PVG CIP. The data format is “twos complement” and is shown in the figure below.

1 byte	----SIGN	MSB		--------------------------------------------------------			-------------------------------------------------------------------Prop1
2 byte	SIGN----	MSB --------------------------------------------------------					Prop2--------------------------------------------------------------------
3 byte	SIGN----	MSB --------------------------------------------------------					Prop3--------------------------------------------------------------------
4 byte	SIGN----	MSB --------------------------------------------------------					Prop4--------------------------------------------------------------------
5 byte	rest_Prop4 - LSB				rest_Prop3 - LSB		rest_Prop2 - LSB		rest_Prop1 - LSB
6 byte	Push 8			Push 7	Push 6	Push 5	Push 4B	Push 4A	Push 3B	Push 3A
	8 bit			7 bit	6 bit	5 bit	4 bit	3 bit	2 bit	1 bit
SIGN = +/−
MSB	= Most significant bit
LSB	= Least significant bit

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PVG CIP specification

§ When using PVEO

Ñ When using PVEM/H/S

Electrical

	PVE outputs	8
	PVE types that can be connected	PVEO, PVEM, PVEH, PVES incl.
		versions with float position
	PVPX/PVPE outputs	1
	Resolution	9 bit (-100% to +100%)
		AMP part no. 1-967280-1, PCB-connector
		AMP part no. 1-967281-1, Timer house
	Plug type	AMP part 0-929937-1, junior contact
	(Only part no. 1-967280-1 supplied with PVG)	AMP part 0-962876-2, micro contact
		AMP part no. 0-965643-1, cover
		Seals and plugs
	CAN setting	Slave only

Plug connections

Pin number	Name
1	PVPX out
2	CAN+
3	CAN+
4	Alarm_1
5	Alarm_2
6	Gnd
7	Alarm_3
8	Alarm_4
9	Alarm_5
10	Gnd
11	Alarm_6
12	Alarm_7
13	Alarm_8
14	Gnd
15	Udc
16	CAN_TERM
17	Gnd
18	PVE1_A §	PVE1 signal Ñ
19	PVE2_A §	PVE2 signal Ñ
20	PVE3_A §	PVE3 signal Ñ
21	Gnd

PVEM/H/S

Pin number	Name
22	PVE4_A §	PVE4 signal Ñ
23	PVE5_A §	PVE5 signal Ñ
24	PVE6_A §	PVE6 signal Ñ
25	Gnd
26	PVE7_A §	PVE7 signal Ñ
27	PVE8_A §	PVE8 signal Ñ
28	Gnd
29	Udc
30	CAN-
31	CAN-
32	PVE1_B §	PVE1 Udc Ñ
33	PVE2_B §	PVE2 Udc Ñ
34	PVE3_B §	PVE3 Udc Ñ
35	Gnd
36	PVE4_B §	PVE4 Udc Ñ
37	PVE5_B §	PVE5 Udc Ñ
38	PVE6_B §	PVE6 Udc Ñ
39	Gnd
40	PVE7_B §	PVE7 Udc Ñ
41	PVE8_B §	PVE8 Udc Ñ
42	Gnd

	Voltage, neutral position		50% of Udc
	Voltage, full flow port A		25% of Udc
		Version with float position control	35% of Udc
	Voltage, full flow port B		75% of Udc
		Version with float position control	65% of Udc
	Voltage, float position	Version with float position control	80% of Udc
	control
	Alarm input signals	Low	< 1,6 V
		High	> 85% of Udc
	Max. linearity deviation		3%
	Max. pulsation content	(f > 2 kHz)	5%
	Max. band width		10 Hz
	Max. output current		± 1 mA

PVEO			PVPE/PVPX
Max. output current	1,2 A		Max. output current			3 A
			Note: To ensure maximum safety, the normally open (NO)
			version of PVPE/PVPX is recommended.
Environmental data
IP classification				IP 66, IEC 529

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Prof 1 CIP specification		Electrical
		Proportional signals max.		4
		Resolution		9 bit (-100% to +100%)
		Operating buttons on/off max.		6
		DIP switch settings	DIP no. 1	Open	= CANopen min. master
				Closed	= CANopen slave
		DIP switch settings	DIP no. 2	Open	= Default baudrate and Node id
				Closed	= Baudrate and Node id acc. to OD
				AMP part no. 282404-1, male plug
		Plug type		AMP part no. 282403-1, female plug
				AMP 282107-1, tab house
		Only part no. 282404-1 and no. 282107-1 supplied
				AMP 282089-1, plug house
				Seals and plugs

	Plug connections			Environmental/mechanical
	Pin number	Name		As analog version
	1	CAN_TERM
	2	Udc
	3	Frame
	4	CAN+
	5	CAN-

Safety aspects	Both PVG CIP and Prof 1 CIP are designed to
	give maximum safety. They both incorporate
	self-test functions, signal protection and
	‘watchdogs.
	Self-tests

The self-test is performed when power is applied and before any of the PVE outputs are activated. The unit then goes to the operating function and a series of running tests are carried out. A list of these tests is given below.

PVG CIP

1.Internal RAM test

2.External RAM test

3.EE-PROM test

4.FLASH test

5.Test of feedback monitoring (tests all outputs for short-circuiting to earth and Udc)

Prof 1 CIP

1.Internal RAM test

2.EE-PROM test

3.FLASH test

Running tests

PVG CIP

1.Watchdog

2.PVEH alarms

3.Signal protection

To ensure optimum system function, two safety levels are used:

•Fail-safe condition

•Alarm condition

Prof 1 CIP

1.Watchdog

2.Potentiometer control

Fail-safe condition		Alarm condition
PVG CIP	Prof 1 CIP	PVG CIP
PVE forced to neutral position.	Neutral position signal sent from	Alarm signal sent on bus so that
Voltage supply to PVE cut off.	the joystick to all PVEs.	a third unit is able to take appro-
		priate action.
		Depending on OD-index 2108
Alarm signal sent on bus so that	Alarm signal sent on bus so that	subindex 1, PVPX/PVPE dump
a third unit is able to take appro-	a third unit is able to take appro-	valve dumps pressure in alarm
priate action.	priate action.	condition. Because this is an NO
		valve (normally open) voltage
		must be cut off.

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Fail-safe condition arises when faults of the following types occur:

PVG CIP

	Fault code HEX	Description	PVEs that go into fail-safe
			condition
	1000	Generic fault	All PVEs
	5000	System hardware	All PVEs
	5001	Self-test fault, internal RAM	All PVEs
	5002	Self-test fault, external RAM	All PVEs
	5003	Self-test fault, EE-PROM	All PVEs
	5004	Self-test fault, FLASH	All PVEs
	5005	Self-test fault, feedback test # 1	PVE 1
	5006	Self-test fault, feedback test # 2	PVE 2
	5007	Self-test fault, feedback test # 3	PVE 3
	5008	Self-test fault, feedback test # 4	PVE 4
	5009	Self-test fault, feedback test # 5	PVE 5
	500A	Self-test fault, feedback test # 6	PVE 6
	500B	Self-test fault, feedback test # 7	PVE 7
	500C	Self-test fault, feedback test # 8	PVE 8
	500D	Self-test fault, feedback test PVPX	All PVEs
	5016	Watchdog fault	All PVEs
	6300	Joystick data format nonconformance	All PVEs
	8100	Communication fault	No PVEs
	8101	Protection fault PDO1	PVE controlled by PD01
	8102	Protection fault PDO2	PVE controlled by PD02
	8103	Protection fault PDO3	PVE controlled by PD03
	8104	Protection fault PDO4	PVE controlled by PD04

Prof 1 CIP

Fault code hex	Description
1000	Generic fault
5000	System hardware
5001	Self-test fault, internal RAM
5003	Self-test fault, EE-PROM
5004	Self-test fault, FLASH
5005	Proportional voltage outside range
5007	Proportional signal registered without corresponding direction change
500F	Watchdog fault

Alarm condition arises on faults of the following types:

Fault code HEX	Description
500E	PVEH alarm # 1, pin 3
500F	PVEH alarm # 2, pin 3
5010	PVEH alarm # 3, pin 3
5011	PVEH alarm # 4, pin 3
5012	PVEH alarm # 5, pin 3
5013	PVEH alarm # 6, pin 3
5014	PVEH alarm # 7, pin 3
5015	PVEH alarm # 8, pin 3

The table below shows at which settings PVPX/PVPE dumps in alarm condition.

	OD-index 2018	Activation of PVPX/PVPE
	subindex 9 HEX
	0	No PVPX
		=> must not dump in alarm condition
	1	PVPX can be controlled from an external source
		=> must not dump in alarm condition
	2	PVPX controlled from an external source, or by alarm condition
		=> must dump in alarm condition

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Introduction to PVG CIP This component is located near the valve and acts as the interface between PVG and CAN bus. The interface can control up to eight PVEs and 1 PVPX/PVPE.

System parameters can be set in the OD (see overview, page 25), either by using CIP Configuration Tool or with a normal CANopen Configuration Tool.

Setting up PVG CIP can be divided into four main parts:

1)Identification of components

a)Identification of PVE

b)Identification of PVPX/PVPE

2)Setting up connections

a)To other components on bus (Prof 1 CIP)

b)Between data (joystick signals) and PVE/PVPX

3)Setting system-related parameters

a)Baudrate

b)Node identification

c)Softwiring

4)Setting hydraulic-related parameters

a)Deadband compensation

b)Signal gain

c)Flow limitation

d)Software tuning of spool characteristics

e)Ramps (individual on each port, two different settings for each port)

f)Float position control

g)Power saving

These components also contain facilities for fault location, servicing and restoring factory setting.

Component identification To be able to communicate with PVG CIP it is necessary to identify the system components:

•Identification of PVE type

•Identification of PVPX/PVPE type

Identification of PVE type Type identification is used to specify how PVG CIP is to control the PVEs. The types used are specified as follows:

		0: Not accessible
		1: PVEO
	Units	2: PVEM
		3: PVEH/S
		4: PVEM (float position control)
		5: PVEH (float position control)
	Max.	5
	Min.	0
	Standard	3 (PVEH/S)
	Precision	1
	OD index	2018 HEX

PVG CIP output/input will be on the following PVE pins, depending on type

	PVE pins			PVEH/S	PVEM	PVEO
1				+	+	Port A
2				Signal	Signal	Port B
3				Alarm	N/A	N/A
				Frame	Frame	Frame

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