User Manual - SCIMAR Engineering Ltd
Contents
1. O O 42 OG O GO Oo o O Oo o o 0 0 o 15 14 13 12 11 if 9 Illustration 1 Female 15way D Type Pin Signal NC NC NC NC NC NC NC NC oo DI OW HRI O M BAE lloop gt o lloop NC NC NC NC NC Table 2 Connector Pinouts pp a Ha N gt UJ Ha PF gt UT Split Pi UDIO 60 25 L User Manual iLoop Overview The iLoop communication featured in Split Pi devices is an isolated communication device that uses flow of current to send and receive data The iLoop communication protocol can be split into standardised layers as defined by the OSI model Physical Layer The iLoop transceiver in Split Pi devices is a slave device that senses the flow of current to receive data and switches the current on and off to send data A single iLoop master device must be used to supply power to the current loop Currently there is an RS232 iLoop adapter available that supplies current to the current loop and provides a standard RS232 interface for simple connection to a computer Below is a simplified illustration of the master iLoop circuit with it s constant current source and isolated transmitter and receiver The master iLoop schematic is available for I__LOOP_POS I__LOOP_NEG HDR_2 Receive ACPL W611 ACPL W611 Illustration 2 Simplified Master iLoop Circuit integration into an embedded control board or other system The slave iLoop2. circuitry in Split Pi devices is very similar to the master with the omission of the constant current source Split Pi UDIO 60 25 L User Manual 7 The physical communications uses only two wires iLoop and iLoop to send and receive data asynchronously in half duplex mode The communication works at 19200 bits per second sends 8 data bits in a frame has no parity bit has one stop bit and has no flow control It functions in a similar way to RS232 apart from the signals are carried by current flow rather than voltage levels Data Link Layer The iLoop protocol uses addressing in a similar way to IEEE 802 3 Ethernet MAC to communicate with several Split Pi devices connected to the same iLoop It has three addressing modes Direct Group and Broadcast Where direct addressing communicates with a single Split Pi device group addressing with a group of Split Pi device connected to the same iLoop and Broadcast with every Split Pi device connected to that iLoop This allows for multiple groups of Split Pi devices connected to the same controller for instance a group of Split Pi s for each wheel on a vehicle allowing individual wheel speed control Network Layer To begin a communication transaction an eight bit addressing mode word is transmitted on the iLoop to specify whether one or many devices will act on the communication To perform direct addressing send the 8 bit word Ox4E ASCII character N To perform group addressing send the 8 b
3. 30V RHS Current max Reverse Current Right to Left Left Hand Side Output LHS Voltage min 0 5 x Vhs RHS Voltage 15V LHS Voltage max LHS Current max Right Hand Side Input RHS Voltage min RHS Voltage max RHS Current max Split Pi UDIO 60 25 L User Manual 3 Hardware Orientation It is important to familiarise yourself with the handedness of Split Pi Although Split Pi is symmetrical its control circuitry is referenced to the left hand side for ease of use Incorrectly connecting power to the right hand side can cause damage to Split Pi and any connected equipment Side o Ground Terminals With the heat sink at the top position Split Pi so that the ground terminals on both sides are closest to you Ground terminals can be identified by having black or no plastic washers fitted In this orientation the left hand side of the device is naturally to your left and the right hand side is to your right ea Split Pi UDIO 60 25 L User Manual 4 Left Hand Side The left hand side of Split Pi is the input side and should be connected to the DC supply eguipment such as batteries LHS Fuse Positive Ground LHS Terminal LHS Terminal Right Hand Side The right hand side of Split Pi is the output side and should be connected to the eguipment you wish to drive such as a DC motor RHS Fuse Positive Ground RHS RHS Terminal Terminal Split Pi UDIO 60 25 L User Manual Data Connection
4. 79 ASCII A BCDEF GHI J KL MN O Hex 50 51 52 53 54 55 56 157 158 59 ISA 5B 5C 5D 5E 5F Dec 80 181 82 183 84 8 5 186 187 88 89 90 191 192 93 94 95 ASCII P QR S T UVWXYZ Table 8 ASCII Letters Split Pi UDIO 60 25 L User Manual 13
5. RR O i me a RIE 7 Data LNK Etanol oia 8 ING UW Of K Lata iii iia 8 MARS DORA IA rece 9 Calibrated Analo cue Readme A Y O Y da 10 A DDCDdICOS ran ra reina 13 PASCIKEFAbSs herd teh cha hee FER RW NT HNN ON spate NR HN HRN ete 13 Specification Topology Split Pi is the name given to a novel patented DC DC converter technology which is shown in its most generic form in Figure 1 RESERVOIR USED FOR MULTI PHASE SYSTEMS S2 B L1 C3 INOUT FILTER A T 0 IN OUT COMMON Figure 1 Split Pi Patented Topology Switches S are implemented in Power MOSFETs The device is entirely symmetrical and can both source and sink current and convert both up and down from a given supply voltage and for this reason the acronym UDIO Up Down In Out is applied In a MOSFET implementation the device is fully synchronous The absence of any diodes conducting means that there are no irreducible voltage drops and so efficiency can approach 10096 very closely Split Pi UDIO 60 25 L User Manual Control The control circuitry on board Split P1 UDIO 60 25 L uses one side of the device as a voltage reference to control Split Pi which is referred to as the Left Hand Side This provides the user with a simple to follow convention e Left hand side of Split Pi o Input of device o Connected to a power source battery e Right hand side of Split Pi o Output of device o Connected to the equipment requiring control motor e P
6. User Manual Scimar Engineering Ltd Split Pi UDIO 60 25 L AVIV go Split Pi is manufactured under licence from 3D Instruments Ltd by Scimar Engineering Ltd and protected by patent No GB2376357 and worldwide equivalents MAN UDIO6025L Copyright 2010 Scimar Engineering Ltd The information contained herein is subject to change without notice Scimar Engineering Ltd will not be liable for technical or editorial errors or omissions contained herein Split Pi UDIO 60 25 L Edition September 2010 Document Reference MAN UDIO6025L IMPORTANT READ ME FIRST There are some important details to know and do s and don ts to follow before using Split Pi e Split Pi has some features that do not exist in other systems and controls a lot more power than other devices of this size Therefore damage can easily occur to connected eguipment without a good understanding of how Split Pi operates Whilst Split Pi is 10096 symmetrical the internal control is NOT It implements a simple voltage ratio control which works by reference to the voltage on the Left Hand side terminals e DO Read the Hardware Orientation section in the User Guide to establish the Handedness of Split Pi Devices that the user connects to Split Pi must be able to sustain current flow in the directions that the user commands by varying the voltage ratio The GENERAL case is given below Left Hand Side LHS Right Hand Side RHS Primary Power Sou
7. dEEPROM command Y 0x59 to read the calibration data from Split Pi s EEPROM along with the following table of addresses The highlighted locations are the most revelant Location Name Location Name Location Name Hex Hex Hex 0x00 Address O 0x01 Address 1 0x02 Address 2 0x03 Address 3 0x04 Address Length 0x05 Group Address 0x06 Control State 0x07 Upper Limit 0x08 Lower Limit 0x18 NA 0x09 Firmware Version 0x19 NA Ox0A Calibration Version Ox1A NA Ox0B Serial Number 0 Ox1B NA Ox0C Serial Number 1 Ox1C NA Ox0D Serial Number 2 Ox1D NA OxOE Serial Number 3 Ox1E NA Ox1F NA Table 5 Main EEPROM Mapping For example to read the ADC Bits only accessible using direct addressing NFEYAOOF Split Pi UDIO 60 25 L User Manual 10 Split Pi will return two ASCII characters for example OC in ASCII Hex converted to a decimal value this is 12 Each of the values stored in EEPROM are 8bits Two bytes must be combined to get the 16bit value of M or C where M M1 MO and C C1 CO Once you have the calibration data you will need to read the ADC using the ReadADC command I 0x49 The following table shows the ADC channels Channel ASCII Hex Value Description 0 00 Voltage Left 1 01 Voltage Right 2 02 NA 3 03 NA 4 04 Current Left 5 05 Current Right 6 06 Temperature Left Bridge 7 07 Temperature Right Bridge Table 6 ADC Channels For example t
8. it word 0x47 ASCII character G To broadcast to all devices either Direct or Group addressing can be used as it uses a broadcast address Then an eight bit address will be transmitted to specify the Split Pi device s that should further act on the communication As default all Split Pi devices come programmed with the address OxFE The broadcast address is OxFF Then an eight bit command word followed by variable length arguments specifying the action that the Split Pi device s should take Some commands are then followed by a variable length response from a Split Pi device The FT structure and on TT is shown below 8 Bbits 8 bits 8 bis 8 32 bits 8 32 bits Mode Table 3 iLoop Message Frame Split Pi UDIO 60 25 L User Manual S Transport Layer The commands are summarised in the table below Command Address Argument Response D EE eet mm Description ASCII Hex Mode Bytes Bytes h i ae etvoti vosa fe fe fo h i O Set the node s voltage ratio X 0x58 1 code to hotstart Get th d i GetStatus S 0x53 2 ep bh R h ified AD ReadADC ead the nodes specified ADC 0x49 1 gt channel Read a byte from a specified ReadEEPROM address within the nodes Y 0x59 2 1 EEPROM ircuit halt vol a oe conversion Set the node s group ID and SetGID store in EEPROM J Ox4A G 1 h GetGID Get the nodes currently active P 0x50 1 group ID Set the full node ID and store ep bh es ff h i
9. o read the left hand side current direct addressing only NFEIO4 Split Pi will return four ASCII characters representing a 16 bit value for example 096F which converted to decimal is 2415 To convert this to a human readable value run this through the previous eguation with the related M and C values for left hand side current For example Left Current MO at location 0x20 0x62 Left Current M1 at location 0x21 0x51 therefore M M1 M0 0x5162 20834 decimal Left Current CO at location 0x22 0x30 Left Current C1 at location 0x23 0x80 therefore C C1 C0 0x8030 32816 decimal ADC Bits at location OxOF Ox0C 12 decimal and as in the previous example Left Current Channel 0x04 reads 0x096F 2415 now put them into the equation Actual Value 10 M ADC 21 P x C Current u A z20834 2415 21 x 32816 Split Pi UDIO 60 25 L User Manual 11 Current z2083412415 0 0625x32816 Current 20834 2415 2051 Current 20834 364 Current 7583576 u A Current 7 584 A Split Pi UDIO 60 25 L User Manual Appendices ASCII Tables Hex 30 31 32 33 34 35 36 37 38 39 Dec 48 49 50 51 52 53 54 55 56 57 ASCII O 1 2 3 4 5 6 7 8 9 Table 7 ASCII Numbers Hex 40 41 42 43 44 45 146 47 148 49 4A 4B 4C 4D 4E 4F Dec 64 165 166 67 168 169 70 71 72 73 74 75 176 77 78 1
10. ositive current from Left to Right The right hand side voltage is governed by a 256 code 0 255 real time programmable ratio The right hand side voltage can be calculated using the equation V lhs V rhs ratio 1 28 The following chart illustrates the operational right hand side output range of Split Pi with different left hand side input voltages RHS Voltage Output for a given Ratio Code 60 50 40 15V Ihs 30 30V Ihs 45V Ihs 60V Ihs 20 10 0 0 32 64 96 128 160 192 224 256 Ratio Code Decimal Voltage Vrhs Since Split Pi is symmetrical allowing current in and out voltage up and down situations can occur where power transfer is in the reverse direction right to left such as regenerative braking by a right hand side motor recharging the left hand side supply battery Due to its left hand side controller reference Split Pi should never be connected in a reverse fashion with battery supply on the right as this can damage Split Pi UDIO 60 25 L User Manual 2 Split Pi and any connected eguipment Table 1 shows the input and output ranges of Split Pi in positive and negative current directions Table 1 Split Pi IO Range Parameter Value Unit Conditions Positive Current Left to Right Left Hand Side Input LHS Voltage min LHS Voltage max LHS Current max Right Hand Side Output RHS Voltage min RHS Voltage max 2 x Vins LHS Voltage gt
11. rce Primary Load eg rechargeable battery eg DC motor or other power source capable of reverse current or Secondary Power Source flow such as a battery or capacitor bank e DO NOT pass current into power sources that are not rechargeable e fa secondary power source is used on the RHS then the user should make provision for external switching to enable that source to be connected or disconnected e DO balance the voltage on the Right Hand Side of Split Pi with the voltage of the secondary power source before connecting it The internal control inside Split Pi reguires power to function Internal diode connections route this from both the LHS and or RHS main terminals so this supply can come from either dynamically but this supply must be 15V or more e In operation Split Pi must have the voltage at one side or the other above 15V at all times e The maximum working ratings for the device are 60V 25 Amps at any terminal It is possible to command an output voltage greater than 60V and it is the user s responsibility to remain inside these limits e 30 Amp fuses are fitted because internal dynamic current limiting protects the device in normal operation e DO NOT fit fuses rated above 30Amps Contents SPecI ICA ION ds 1 A a OO YR O ANO aY AUU UO UON 1 A a a 2 Hardware OrientaHonz s rallenta brain asia 4 Ferr a LLO SIG Es FF EE NN EN CN A NN FFF TU FR 5 Risht Hand Sid e dd tisane 3 Data Connect Y A e 6 AA A narnia 7 NA E
12. ve full GetNID Get the currently active fu W 0x57 node ID Refresh the node Recon cont configuration from EEPROM DOD Revert to default Factory configuration Table 4 iLoop Command Set Note 1 Hotstart reguires special care and attention in its use Please see iLoop Manual for more info ResetDefault 0x3F For example to set a voltage ratio of 64 40 hex using direct addressing NFEV40 To set a voltage ratio of 64 using group addressing G55V40 To read the currently set voltage ratio interrogation only uses direct addressing NFEO Split Pi will then return a two character Ascii Hex value of the code i e 40 Split Pi UDIO 60 25 L User Manual 9 Calibrated Analogue Readings Split Pi has a built in Analogue to Digital converter that allows the user to read Voltages applied to the left and right hand sides bi directional Currents at either sides and the temperature of the synchronous switching bridges The values read from the ADC are absolute values and require conversion into real values This is achieved by reading calibration data stored in the EEPROM and running it through the eguation Actual Value 10 M ADC 2 AP x C where M and C are 16 bit values stored in EEPROM ADC s is an 8 bit value stored in EEPROM and ADC is the Analogue to Digital reading M is the actual value of one count of the ADC in microVolts microAmps micro degC C is the zero point offset in ADC counts Use the Rea
Download Pdf Manuals
Related Search