Pressure Sensor – EPT31CN with CAN SignalCANopen Pressure & Temperatur Sensor1. of the EPT transducerThe CAN busCANopenData flow withing the EPT transducerThe Object Dictionary of the EPT transducerElectrical charateristicsInitial operation and application examplesTechnical description1. Introduction1.1 Abbreviation indexThe following table shows the used abbreviations within this ast-significant bit/byteMost-significant bit/byteService Data ObjectProcess Data ObjectTransmit PDONetwork Management ServiceEmergency ObjectSynchronization ObjectLayer Setting ServicesElectronic DatasheetCommunication Object Identifier1.2 Bibliographical referencesThe following table contains all used references within this document.[1] CAN in Automation, “DS-404 v1.2.0 Device profile for measuring devices and closed-loop controllers,” 2002.[2] CAN in Automation, “CiA 305: Layer setting services (LSS) and protocols,” 2013.[3] CAN in Automation, “CANopen vendor-ID,” [Online]. Available: https://www.can- [Accessed 2 August 2017].[4] CAN in Automation, “DS-301 v4.2.0 CANopen application layer and communication profile,” 2011.[5] CAN in Automation, “DRP 303-2 v1.0, Representation of SI Units and Prefixes,” July 1999.[6] H. Schmidt, “IEEE-754 Floating Point Converter,” [Online]. Available: ml. [Accessed October 2017].1.3 PrefacePlease read this document conscientiously before using the EPT pressure/temperature transducers. At any time, keepthis document at a place which all users have access to. Please support us to improve this document and the EPTpressure/temperature transducer product. Chapter 8 contains useful application examples helping to perform thefirst steps with the EPT transducers.Variohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehaltenStand 07/2017

2. Features of the EPT transducer2.1 General featuresEPT transducers are intended to be used for pressure and/or temperature acquisition of liquid and gaseous media.The pressure and temperature measurements are being digitalized, linearized and made available via the CANopeninterface. Besides the CANopen standard feature set (CiA 301/404), EPT transducers offer many useful functions –amongst them are, for example:Full support of CAN 2.0 A and CAN 2.0 B identifiersTwo separate measuring channels for EPT pressure transducers: The primary measuring channelcarries pressure measurements, the secondary measuring channel offers coarse temperaturevalues ( 5K). EPT temperature transducers feature only one measuring channel.Almost all internal calculations are being performed using a hardware floating-point unit. Thus,calculating is performed at highest precision and speed. Impulse response goes down to 2𝑚𝑠.Stay-set indicators (slave pointers) for keeping track of the minimum and maximummeasurements applied to the sensor. Each measuring channel features its own set of stay-setindicators,Flexible 5-stage IIR filters (one for each measuring channel) which fulfil almost every situation’sneeds. Their coefficients are typically configured as “floating average filter”,A Clamping unit allowing to apply a limited range to all measurements which cannot be exceeded,Various interrupt sources for event driven measurement transmission,Possibility to replace the Linear Scaling Unit (CiA 404, [1]) with one of numerous transferfunctions: Customers can, for example, order transducers that perform deviations, integrations,polynomial functions or spheric/cylindric fill grade approximations.The nominal operating temperature ranges from -40 C to 125 C; a summary of all (electrical and nonelectrical) limitations is located at section Optional hardware featuresThe following hardware features can optionally be included in the EPT pressure/temperature transducers:There are various options for included CAN bus termination:o Pure resistive termination (120Ω),o Split termination (2𝑥 60Ω 4.7𝑛𝐹; should be preferred over the resistive termination),o Switchable termination. The termination state (enabled/disabled) can be configured using SDO;the operating temperature range will be limited to -40 C 105 C.Galvanic isolation of the bus lines. This feature introduces the additional wire CANGND/GNDCAN whichotherwise is not present. The operating temperature range will be limited to -40 C 100 C.Variohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehalten

3. THE CAN BUS3.1 Transmission speed / bit rateThe bit rate represents the bus communication speed; it must be the same for all participants. There are physical andconceptional limits concerning the bit rate:The longer the bus wiring, the smaller the bit rate that can be applied. By rule of thumb, the wiringlength should not exceed 25m at 1 𝑀𝑏𝑖𝑡/𝑠 and 500m at 125 𝑘𝑏𝑖𝑡/𝑠,The faster the communication speed, the higher the “EMC pollution”. That’s why the bit rate shouldbe chosen only as high as necessary. A good trade off will be made with a bit rate of 125 𝑘𝑏𝑖𝑡/𝑠,Due to timing reasons, the EPT pressure/temperature transducers do only support bit rate valueswithin the following range: [20 𝑘𝑏𝑖𝑡/𝑠 1.5 𝑀𝑏𝑖𝑡/𝑠].CANopen defines a set of standard bit rates of which the majority is supported by the EPT transducers. Refer tothe bit rate table located at section 4.13. Besides these pre-defined bit rates, it is possible to define customerspecific bit rates when placing the order.For changing the bit rate, the EPT transducers implements the LSS service. While the standard bit rates areaccessible at table selector 0, customer defined bit rates will be made available at the table selector 1. If desired,please explicitly point out to define a customer defined bit rate table (selector 1) when placing the order!The EPT pressure/temperature transducers’ standard bit rate is 125 𝑘𝐵𝑖𝑡/𝑠.3.2 CAN framesCAN frames represent the messages sent over a CAN bus. A CAN frame consists of multiple data fields; some ofthe most important fields are:Identifier, amongst other things used for expressing the priority of a CAN frame. According to CAN2.0 A, the identifier has a length of 11 bits; CAN 2.0 B raised the length to 29 bits,Data length code (DLC) holds the amount of data bytes contained in the CAN frame,The data fields contain the actual frame data. There can be between 0 and 8 data bytes.EPT pressure/temperature transducers support both CAN 2.0 A and CAN 2.0 B frames.Variohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehalten

4. CANOPEN4.1 Node-IDThe Node-ID identifies a CANopen device within an application network and therefore must be unique. Valid Node-IDsare of data type uint8 and range from 1 to 127 (0x01 0x7F). EPT pressure/temperature transducers do support NodeID configuration via SDO and LSS.The standard Node-ID for EPT transducers is 32 (0x20).4.2 COB-IDThere are many communication objects within a CANopen network (the word ‘Communication Object’ can besubstituted with ‘CAN message’). Those are, for example, objects for SDO, PDO, SYNC, EMCY and NMT. Each of thesecommunication objects relates to a certain CAN Identifier which (accumulated with some additional control bits) resultsin the so-called COB-ID (“Communication Object Identifier”).All COB-IDs used and provided by the EPT pressure/temperature transducers can be modified via SDO.4.3 Network Management Service (NMT) and boot-up behaviourEach CANopen device implements the NMT state machine. Most of the network members act as a NMT slave; theirstate machine will most likely be controlled by the network NMT master. The NMT state machine provides thefollowing Stopped.When booting-up, a EPT pressure/temperature transducer sends out a boot-up message and usually settles itsstate machine in ‘Pre-Operational’ state. The device is now performing measurements, but is not able toautomatically output them using the PDO service.In order to enable PDO, the NMT state machine must be transitioned to ‘Operational’ state. This can be eitherdone by transmitting a Start-Remote-Node message or by configuring the device to directly settle in ‘Operational’state (this behaviour is referred to as Autostart; see section 6.1.20).The following CAN message represents a NMT Start-Remote-Node message which transitions all presentNMT slaves to ‘Operational’ state in order to enable measurements output (PDO):CAN-ID (hex)0x000DLC2Data bytes (hex)0100This NMT message transitions all present NMT slaves to ‘Operational’ stateA CANopen devices usually implements a set of network services. These services’ accessibility depends on the NMTstate the devices currently reside in. The following table shows the availability of services implemented by the EPTtransducers.Variohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehalten

NMT stateAvailable servicesInitialization-Pre-OperationalNMT, HBC, TIME, LSS, EMCY, SDO,OperationalNMT, HBC, TIME, LSS, EMCY, SDO, SYNC, PDOStoppedNMT, HBC, TIME, LSSHBC . Heartbeat ConsumerA NMT Slave (like the EPT transducers) typically is not allowed to automatically transfer its state machineto other states. The only two exceptions are made 1) with the Autostart behaviour which was already described above,2) in case of emergency situations (sensor faults, etc.): The NMT state machine is able to transfer itself to‘Pre-Operational’ or ‘Stopped’ (depending on the configurations made to object 0x1029, Error Behaviour;refer to section 6.1.17).4.4 The Object DictionaryThe Object Dictionary plays a central role in CANopen. It represents a table of variables (objects) that can beaccessed for configuring and inquiring a CANopen device’s state. Each table entry can be accessed with acombination of a 16-bit index and an 8-bit sub-index – thus there are 65536 indices whereof each index features upto 256 sub-indices. The Object Dictionary is accessible using Service Data Objects (SDO).The EPT pressure/temperature transducers’ Object Dictionary is split into three parts:DS-301,DS-404,Manufacturer specific objects.Section 6 deals with the supported objects and describes how to use them.4.5 Service Data Object (SDO)Service Data Objects are used to read and write variables from the Object Dictionary. These variables may containsettings or status/informational data, depending on the address (index and sub-index) that is being accessed. EachCANopen device provides at least one SDO channel which two CAN Identifier are assigned to.There are two types of SDO accesses: Expedited SDO and Segmented SDO. Expedited SDO accesses are intended fortransferring values not longer than 4 bytes – these accesses are the preferred way of performing SDO accesses toEPT transducers.Segmented SDO accesses are necessary for transferring data that are longer than 4 bytes. This type of access willonly be necessary for reading string data (VISIBLE STRING).A typical SDO access consists of five important things:1) Address (Node-ID) of the CANopen device that is being accessed,2) Access code (read/write, as well as the type of the accessed datum; will be discussed below),3) Index of the object that is being accessed (16 bits),4) Sub-index of the object that is being accessed (8 bits),5) In case of write accesses: The data that shall be written (up to 4 bytes).Variohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehalten

The table below shows the supported data types and their SDO access codes for reading/writing.Data typeLength inbytesPreferred SDOaccess typeAccess codeReadingBOOLEAN1Expedited0x400x2FInt8, Uint81Expedited0x400x2FInt16, Uint162Expedited0x400x2BInt32, Uint324Expedited0x400x23Float32 (REAL)4Expedited0x400x23Segmented0x40N/AVISIBLE STRINGAccess codeWritingSDO is a confirmed service. This means that all read and write accesses will be answered. The response’s firstdata byte does always contain an error code signalling if the SDO access was successful. The table below shows aset of possible SDO error codes.SDO error codeDescription0x41Segmented read transmission initiated. Refer to reading succeeded, unspecified data length (or 0 bytes).4 bytes available.0x430x470x4B0x4F3 bytes available.Expedited reading succeeded,2 bytes available.1 byte available.0x60Writing succeeded.0x80Error occurred. The last four data bytes contain more specific information.The following sub-sections describe how to perform the two types of SDO accesses in order to read and write datafrom/to the Object Dictionary.4.5.1 Expedited SDOExpedited SDO will (as already described above) be used in order to access data values that are not longer than 4bytes. This applies for all available data types – except for VISIBLE STRING.The following figure shows how to build up a CAN message containing a valid SDO access.Index (Little Endian!)SDO access code (see codes above)CAN-ID (hex)DLC0x600 Node-ID8Sub-indexWrite: Data to be transferredRead: Set to zeroData bytes (hex)22341211DDCCBBAAExemplary Expedited SDO access for writing a value to object 0x1234 (sub-index 0x11).Variohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehalten

A possible response to this SDO write access could be as follows:SDO error code (0x60 „write success“)CAN-ID (hex)DLC0x580 Node-ID8Index (Little Endian!)Response to writing: Set to zeroResponse to reading: DataSub-indexData bytes (hex)6034121100000000Exemplary SDO response to writing a value to object 0x1234 (sub-index 0x11).4.5.2 Segmented SDOSome data are larger than 4 bytes; their transmission will be done using Segmented SDO. Segmented transmissions areinitiated in the same manner as Expedited SDO. Please be aware that the EPT pressure/temperature transducers do onlysupport Segmented SDO in order to read values – writing is not possible.The following example shows how to read the contents of object “Device Name” (0x1008, sub-index 0).1) The following CAN message contains a regular SDO read access to the desired object.Index (Little Endian!)SDO access code (see codes above)CAN-ID (hex)DLC0x600 Node-ID8Sub-indexMust be zeroData bytes (hex)4008100000000000Step 1: Exemplary initiation of Segmented SDO access in order to read the contents ofobject “Device Name” (0x1008, sub-index 0).If the object Device Name actually holds a string and its length exceeds 4 characters, the SDO response contains theerror code 0x41 – which indicates that a segmented transfer was initiated. The following message shows such anexemplary SDO response.CAN-ID (hex)DLC0x580 Node-ID8Data bytes (hex)410810000C000000Step 1: The response code 0x41 indicates that a segmented transfer was initiated. Theamount of readable data bytes is 12 (0x0C; data byte 5).2) Now, the next segment of 7 bits will be inquired. Therefore, the following message needs to be sent. The firstdata byte holds a specific value (0x60 or 0x70) that must be toggled with each inquiry. Initially, this togglingvalue is 0x60.CAN-ID (hex)DLC0x600 Node-ID8Data bytes (hex)60/7000000000000000Step 2: Inquiring the next 7 data bytes. The first data byte must be toggled each time; initially it is 0x60.Variohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehalten

The response’s first data byte does contain some protocol overhead, splitting up into two parts: The uppermost four bitshold a toggling value, which assumes either 0x0 or 0x1. The lower four bits usually read zero; but in case of the lastsegment, they provide the amount of valid data bytes (1 7).The following two messages show valid responses. Message a contains exemplary data originating from the middle of asequence of transfers. Message b represents the last message out of a sequence of transfers.CAN-ID (hex)DLC0x580 Node-ID8Data bytes (hex)t048656C6C6F2057Step 2a: Exemplary data segment originating from the middle of a sequence of transfers. tstands for the uppermost four bits which contain the toggling value (0x0 or 0x1).CAN-ID (hex)DLC0x580 Node-ID8Data bytes (hex)410810000C000000Step 2b: Exemplary data segment representing the last message out of a sequence of transfers. tstands for the uppermost four bits which contain the toggling value (0x0 or 0x1).When put together, the both messages’ data contents result in the following hexadecimal byte sequence:48 65 6C 6C 6F 20 57 6F 72 6C 64 21, which stands for the ASCII-encoded string “Hello World!”.4.6 Process Data Object (PDO)The main purpose of Process Data Objects (PDO) is to transfer process data (like pressure values) from one CANopendevice to another. There are two kinds of PDOs which are a result of the specific data direction: inbound PDOs arereferred to as RPDOs, outbound PDOs are called TPDOs. EPT transducers do support the transmission of PDOs andthus are TPDO producers.When it’s time for transferring a TPDO, the device generates the CAN message’s data contents according to theindividual TPDO mapping settings. TPDOs can only be transmitted as long as the NMT state machine (see 4.3) residesin the state ‘Operational’.Each EPT transducer features two TPDOs. These TPDOs can be configured individually (refer to sections and6.1.19); examples for available settings are:Transmission trigger (timer, SYNC, event-driven),Enable/disable the transmission (TPDO2 is typically disabled by default),CAN identifier,TPDO mapping.Both of the TPDOs each offer a set of up to eight mappings which can be assigned with several objects from DS-301,DS-404 and the manufacturer specific section. Their particular chapters (6.1, 6.2 and 6.3) offer tables summarizingwhich objects are available for mapping. By default, only the Process Value (primary measuring channel) is mapped toboth TPDOs.4.7 Synchronization Object (SYNC)The Synchronization Object (SYNC object) is intended to synchronously initiate PDO transmission of multiple devicesin the entire network. The SYNC object is supported by the EPT transducers.Variohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehalten

4.8 Emergency Object (EMCY)An Emergency Object (EMCY) is issued as soon as an error could be detected by a CANopen device. The EPT transducersadditionally feature a volatile storage which holds up to fifty previously occurred errors; it is available at object index0x1003 (see section 6.1.4).The EMCY’s CAN Identifier typically is 0x80 Node-ID. The EMCY data bytes will be arranged as follows:MSBLSB16 bits8 bits16 bits24 bitsEMCY codeError register(object 0x1001)AdditionalinformationReserved (zero)The following table contains a set of possible EMCY codes:EMCY codeError class0x0000-0x5030Sensor errorDescriptionError reset or no error.Sensor error occurred. See fieldAdditional Information.0x8100Generic communication error.0x8110CAN overrun.0x81200x8130CAN is now in state Error Passive.Communication errorHeartbeat was not received.0x8140Recovered from Bus Off.0x8150CAN-ID collision.In case of the EMCY code 0x5030 (Sensor error), the field Additional Information contains more preciseinformation. It might be helpful to supply the manufacturer with the field’s contents. The following tablecontains a set of exemplary values:Additional InformationDescription0xC555A/D watchdog error0xCFCFBond wire broken4.9 Time Stamp Object (TIME)This CANopen device is capable of producing and consuming Time Stamp Objects. The EPT transducersimplement an internal, milliseconds-based, permanently increasing time stamp which can (provided thedevice acts as TIME consumer) be synchronized with a network-wide time base.In order to associate measurements and time stamps, the respective time stamp values are mappable toPDOs.The TIME behaviour can be configured using the object COB-ID time stamp (0x1012; refer to section 6.1.11).Variohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehalten

4.10 HeartbeatFor means of ensuring operability of network nodes, CANopen offers, inter alia, the automatic transmission ofheartbeat messages: each node can be configured to cyclically transmit a certain message in order to signal itsreadiness.EPT transducers are able to generate and to consume heartbeat messages. The configuration is done by using objects0x1016 and 0x1017 (refer to sections 6.1.13 and 6.1.14). The CAN Identifier used for heartbeat cannot be altered andcalculates as follows:CAN-IDHeartbeat 0x700 Node-ID4.11 Electronic Datasheet (EDS)Most functions of the EPT pressure/temperature transducers are controlled by objects which are summarized withinthe Object Dictionary. The Electronic Datasheet provides a method to reflect the entries of the Object Dictionary to astandardized text-based file. These files can be read and interpreted by almost any software that implementsCANopen functions.The EPT transducers’ EDS file reveals the manufacturer’s default configuration; it can be obtained from [2].4.12 Layer Setting Services (LSS)The EPT transducers implement the Layer Settings Services (see [3]) in order to change Node-ID and bit rateof a CANopen node.Be aware that, if LSS is used to change a device’s Node-ID, some COB-IDs do not automatically adapt to the newNode-ID. If this is desired (what indeed most likely will be the case), usage of the object 0x4001 (see 6.3.6) should begiven preference. Section 8.3 shows how to easily apply an alternative Node-ID.When changing the bit rate, the user has the option to either use the pre-defined CANopen bit rate table (tableselector 0; see Table 1), or to refer to a user-defined table (table selector 1). The user-defined table can hold up to 5customer specific entries; please be aware that table must be defined when placing the order!Bit rateBit rate code11000 kbit/s0800 kBit/s1500 kBit/s2250 kBit/s3125 kBit/s4100 kBit/s550 kBit/s620 kBit/s7Table 1: Available standard bit rates according to [3] (bit rate table selector 0)Section 8.4 explains step-by-step how to configure a EPT transducer’s bit rate using LSS.1 The bit rate code is used when configuring the bit rate using LSS.Variohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehalten

5. Data flow within the EPT transducerEPT transducers feature a complex data path which will be applied to each measuring channel; see Figure 1. Each of thedepicted objects offers at least two sub-indices in order to configure both measuring channels independently.The measuring channels’ assignment and thus the assignment of sub-indices depends on the kind of transducer:Pressure transducers offer two channels. The primary measuring channel refers to pressure, the secondary channelprovides coarse temperature values,Temperature transducers offer only the primary measuring channel, which stands for temperature.Figure 1: Data flow within the EPT transducersVariohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehalten

Almost all functional blocks from the data path are configurable using SDO. The respective object indices wereannotated directly next to the blocks. While most of the functional blocks originate from [1], some of them can befound in the manufacturer specific objects section. For detailed descriptions regarding the objects depicted above,please refer to the sections 6.2 and 6.3.Filter UnitThe Filter Unit is the only functional block that cannot be configured using SDO. DS-404 (refer to [1]), in fact,intends to support the configuration of certain filter types and therefore offers two objects; the IIR filter however isfar too complex be reduced to two objects.The implemented filter represents a 5-stage IIR filter (“Infinite Impulse Response”). Figure 2 illustrates its generallogical structure.Figure 2: 5-stage IIR Filter UnitAs seen above, the implementation of an IIR filter relies on multiple coefficients – in the case of a 5-stagefilter, there are eleven coefficients. With skilful selection of suitable values, many different filter types can berealized, such as: Butterworth, Chebyshev, et cetera. By default, the function of a floating average filter isfulfilled. If desired, customers may define specific filter coefficients when placing the order.Scaling Unit (and alternative transfer functions)DS-404 (see [1]) suggests the implementation of a Scaling Unit in order to perform linear transformations onField Values, which subsequently are referred to as Process Values. EPT transducers follow this suggestion;they implement the Scaling Unit as standard transfer function.Alternatively, if desired, customers may ask to implement other transfer functions. Already implementedfunctions are, inter alia, deviations, integrations, polynomial functions or spheric/cylindric fill gradeapproximations. The handling of alternative transfer functions is – neither switching from one function toanother, nor the configuration of single functions – not yet implemented in the form of SDO accesses. Thus,customers should be indicating their desire for an alternative transfer function when or before placing theorder.Input offsetThe Input Offset bases on the Field Value, not on the Process Value (as proposed by DS-404; [1]). Benefit isdata consistency, as the offset value does not change as soon as any settings are made to the Scaling Unit.In order to prevent confusion, the two objects 0x3124 and 0x3125 were introduced. Refer to section 6.3.1.Variohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehalten

6 The object dictionary of the EPT TransducerThe following sections describe the accessible entries of the EPT pressure/temperature transducer’s ObjectDictionary.6.1 Communication Profile Specific Entries 0180x10200x10290x1800 . 0x18010x1A00 .0x1A010x1F80MeaningDevice typeError registerManufacturer status registerPre-defined error fieldCOB-ID SYNCManufacturer device nameManufacturer hardware versionManufacturer software versionStore parametersRestore default parametersCOB-ID time stampCOB-ID EMCYConsumer heartbeat timeProducer heartbeat timeIdentity objectVerify configurationError behaviour objectTPDO communication parameterTPDO mapping parameterMappable to TPDO? NMT startup behaviour6.1.1 0x1000 (Device Type)This object provides information about the device type. Ist contents are constant and thus not writable.Sub-index0Data typeUint32AccessCONSTNote0x80 02 01 9426.1.2 0x1001 (Error register)Provides information on the error status of the A/D sensor part. It is part of the EMCY message and may bemapped to a TPDO.Sub-index0Data typeUint8AccessRONoteLowest bit (“Generic Error”) contains ‘High’in case of a device-internal A/D error.2 The lower 16 bits part holds the device profile number (404 ). The upper 16 bits contain additional information.10Variohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehalten

If this error field once contains an error, it can only be reset to zero with a power-off, power-on sequence. That is becauseof the high severity of A/D errors.More fine-grained error information may be inquired using the manufacturer status register (0x1002; see 6.1.3).6.1.3 0x1002 (Manufacturer status register)This field combines the two status bytes of each temperature and pressure channel (0x6150; see 6.2.5).The value contained regardsthe error status of the A/D path,beyond-maximum-limits information for primary and secondary measuring channels (usually pressure andtemperature).Sub-index0Data typeUint32AccessRONoteSee below.The data contents are assembled in the following manner:MSBLSB16 bitsReserved for future use8 bits8 bitsSecondary channel3status byte(usually temperature)Primary channel3status byte(usually pressure)6.1.4 0x1003 (Pre-defined error field)This object provides history about the errors signalled via the EMCY message (see 4.8).Sub-indexData typeAccess0Uint32RW0x01 0xFEUint32RONoteRead access: Number of errors (0x00 0xFE)Write access: Writing zero deletes history.See below.Each newly triggered error is assigned to the sub-index 0x01. The sub-indices of all previous errors will beincremented by one. The 32-bit error field consists of two 16-bit values.MSB16 bitsAdditional informationLSB16 bitsError code3 In case of explicit temperature sensors, the primary channel refers to temperature. The secondary channel statusbyte may then be neglected.Variohm Eurosensor Ltd. Hans Buntes Straße 8 69123 Heidelberg [email protected] 49 (0)6221 772 233Änderungen und Irrtümer vorbehalten

The field “Error code” holds the EMCY error code defined by CANopen. In case of a sensor error, this fieldcarries the value 0x5030 (“Sensor fault”).The field “Additional information” contains the same-named field originating from the EMCY message. In case of0x5030 (“Sensor fault”), it might be helpful to supply the

NMT Network Management Service EMCY Emergency Object SYNC Synchronization Object LSS Layer Setting Services EDS Electronic Datasheet COB-ID Communication Object Identifier 1.2 Bibliographical references The following table contains all used references within this document. [1] CAN in Au