HA7E-User Manual - Embedded Data Systems
Contents
1. Command Response no checksum P lt CR gt Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 14 15 RJ 11 PINOUT RJ11 PIN SIGNAL DESCRIPTION 1 No connection No connection 2 No connection No connection 3 1 Wire Input Output Pin Microlan network I O 4 1 Wire Ground Pin Microlan ground 5 No connection No connection 6 No connection No connection DB9 PINOUT SIGNAL 9 PIN CONNECTOR RS232 RS485 TTL DB9 Signal DESCRIPTION FUNCTION NC 1 NC No connection TXD 2 Transmit Data TXRX TX output RXD 3 Receive Data T XRX RX input DTR 4 PWRIN1 input power DTR diode blocked RTS 7 PWRIN2 input power RTS diode blocked GND 5 Ground reference NC 6 NC No connection NC 8 NC No connection NC 9 NC No connection PARAMETER SYMBOL MIN TYP MAX UNITS Supply Voltage Vec 6 16 5 Volts Supply Current during command l 2 3 4 mA Strong Pullup Short Circuit current lsc 35 mA Supply Current quiescent Iq 60 100 400 MicroAmp 1 Wire devices 100 devices CAT 5 Cable length 0 1000 feet Communications 9600 Baud 8 Bits no parity 1 stop bit Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 15 152. EMBEDDED HA7E User Manual E DS DATA SYSTEMS ASCII RS232 to 1 Wire Host Adapter http www EmbeddedDataSystems com FEATURES ASCII command support for all 1 Wire devices Powered by RS232 handshake lines Automatic power up and power down Automatically provides smart strong pull up 1000 feet 100 devices per CAT 5 twisted net Search Family Search and Conditional Search Block mode commands support all 1 Wire device functions Supports Touch Memory File Structure for Dallas Semiconductor iButtons ESD Protection more than 27kV IEC801 2 Reference Model on the 1 Wire bus Automatic CRC16 for TMEX files ABS enclosure Low Cost DESCRIPTION The HA7E is an RS232 to 1 Wire interface in a very small ABS enclosure designed to provide an ASCII command set for RS232 serial hosts that need to accommodate Dallas Semiconductor iButton and 1 Wire devices The HA7E relieves the host of the burden of generating the time critical 1 Wire communication waveforms while supporting all 1 Wire devices with simple ASCII commands that can be easily generated The HA7E does all the hard work of interfacing 1 Wire networks Small size and very low power consumption as well automatic power up and power down features allow the HA7E to operate in low power and battery operated applications with no need for power control signals from the host device The only interface signal required is the RS23 level TX RX RTS and DTR When a serial ASCII
3. 1D2E00010D2E00010E2E00010F2E00010D2F0001122F0001122F00011312BBD0 lt CR gt Q Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 10 15 READ FILE RECORD Command g B READ FILE RECORD and READ NEXT FILE RECORD Form Lp Where L is the command directive and p is the page number The Read File Record command allows one TMEX file record to be read from an iButton or 1 Wire memory device CRC16 is checked on the record and if the record is not a valid Touch Memory File record an error code BEL 07 is generated The byte count continuation code and CRC16 bytes are stripped from the file record before it is sent See Chapter 7 of the Book of DS19xx iButton Standards from Dallas Semiconductor for a comprehensive discussion of the Touch Memory File Structure Example Read two records of a file starting at page OF from the DS1996 with ROM code EF00000003B7890C Then read the next record of the file after these two Command Response AEF00000003B7890C lt CR gt lt CR gt LOF Response this is pages OF 2E0001142E0001142E0001132E0001112E0001132E0001122E000112 lt CR gt Response page 10 2E0001102E00010F2E0001 112F00010F2E00010E2E0001102E00010E lt CR gt Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 11 15 WRITE File RECORD Command U WRITE File RECORD AT PAGE WITH CRC16 Form Up data lt CR gt Where I is the write r
4. Z 0 lt CR gt write a 1 bit O 1 lt CR gt read a 1 bit O 1 lt CR gt read a 0 bit O 0 lt CR gt Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 8 15 RESET Command R 1 WIRE RESET Form R a single character command The Reset command generates a reset pulse and determines if any slave devices are on the 1 Wire bus Example Reset the 1 Wire bus and determine if any slave devices are present Command Response no checksum R lt CR gt Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 9 15 READ PAGE Command G READ PAGE and g Read NEXT PAGE Command Form Gp Where G is the command directive and p is the page number The Read Pages command allows one page of data to be read from an iButton or 1 Wire memory device No assumptions are made about the nature of the contents of the page See the L read file record command for details on how to read Touch Memory File TMEX records Example Read two pages of data starting at page OF from the DS1996 with ROM code EF00000003B7890C Command Response AEF00000003B7890C lt CR gt AEF00000003B7890C lt CR gt GOF Response this is page OF 1D2E0001142E0001142E0001132E0001112E0001132E0001122E00011210CA42 lt CR gt Response page 10 1D2E00010E2E00010D2E0001 102E00010F2E00010F2E0001102F00010D11A299 lt CR gt Q Response page 11
5. of the next device on the bus must be preceded by S command F FAMILY SEARCH Search command except that only the device with a matching family code will participate in the search f MORE FAMILY SEARCH Search command next matching family code must be preceded by F or f command C CONDITIONAL SEARCH ALARM SEARCH Search command except that only devices fulfilling a specific condition will participate in the search A ADDRESS Select Selects a device on the 1 Wire bus with a matching 64 bit ROM code Z WRITE ZERO BIT This command allows a single zero bit to be written on the bus O WRITE READ ONE BIT This command allows a single one bit to be read or written on the bus or a zero bit to be read R 1 WIRE RESET The Reset command generates a reset pulse on the 1 Wire bus G READ PAGE Allows one page of data to be read from an iButton or 1 Wire memory device g READ NEXT PAGE Read next page from an iButton or 1 Wire memory device must be preceded by G or g command L READ FILE RECORD Allows one TMEX file record of data to be read from an iButton or 1 Wire memory device T READ NEXT FILE RECORD Read next TMEX file record must be preceded by L or I command U WRITE File RECORD AT PAGE WITH CRC16 Write to 1 Wire devices and iButtons in Touch Memory File Structure records W WRITE BLOCK Similar to the write read bit command on blocks of up
6. to 32 bytes M MATCH ROM COMMAND Sends a Reset and a Match ROM command for the currently selected device P POWER DOWN THE 1 Wire Bus The 1 Wire bus and the HA7E will power down at the end of this command Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 2 15 Search ROM Command S SEARCH ROM Form S a single character command When a system is initially brought up the host application might not know the number of devices on the 1 Wire bus or their 64 bit ROM codes The Search ROM command allows the HA7E to use a process of elimination to identify the 64 bit ROM codes of all slave devices on the bus The Search ROM process is the repetition of a simple 3 step routine read a bit read the complement of the bit then write the desired value of that bit The HA7E performs this simple 3 step routine on each bit of the ROM After one complete pass the HA7E knows the contents of the ROM in one device The 64 bit ROM code is then reported as an 8 byte ASCII hexadecimal string Additional passes may identify the remaining number of devices and their ROM codes The HA7E Search ROM command will find the ROM codes of one the first in search order slave device on the bus The host application can remember this ROM code for future references to this slave device with the A address command See Chapter 5 of the Book of DS19xx iButton Standards from Dallas Semiconductor for a compr
7. 0000000836A410 lt CR gt W0144 lt CR gt convert command 44 lt CR gt WAIT 350 MILLISEC FOR CONVERSION TO COMPLETE M match ROM commana 7F0000000836A410 lt CR gt WOABEFFFFFFFFFFFFFFFFFF lt CR gt BE28000000FFFF274B72 lt CR gt f next family search BD0000001D323910 lt CR gt WAIT 350 MILLISEC FOR CONVERSION TO COMPLETE M match ROM commana BD0000001D323910 lt CR gt WOABEFFFFFFFFFFFFFFFFFF lt CR gt BE28000000FFFF274B72 lt CR gt f next family search lt CR gt no more DS1820 DS1920s Note It can be seen from this example that the host does not need to maintain the ROM codes of the devices in the network in order to acquire data and communicate with them This example uses the family search command to select the DS1820 DS1920 devices and the W command to acquire the temperature data SESE SS SS SS ae Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 4 15 Conditional Alarm SEARCH Command C CONDITIONAL SEARCH ALARM SEARCH c NEXT CONDITIONAL SEARCH Form C a single character command Form c a single character command The Conditional Search ROM command operates similarly to the Search command except that only those devices fulfilling a specific device dependent condition will participate in the search This is a very powerful functional aspect of 1 Wire devices This capability provides for very fast and efficient polling of the 1 Wire bus for devices that
8. Once a device has been selected subsequent commands can operate on it without the need to select it again The HA7E will remember the ROM code of a selected device and automatically use it when necessary to re address the selected device without the users need to re send the ROM code ROM codes are determined with the S search M match ROM and F family search commands The Address command selects the 1 Wire device that corresponds to the ROM code in the command Devices may also be selected with the F family search S search or M match ROM commands Once selected all commands will operate on the selected device until another device is selected Example Select the DS2407 with a ROM code of 0600000001C8BE12 then read the channel info byte with the W command Command Response A0600000001C8BE12 lt CR gt 0600000001C8BE12 lt CR gt WO4F5FFFFFF lt CR gt F5FFFFA6 lt CR gt The channel info byte is A6 the last byte See the DS2407 specification from Dallas Semiconductor SESE SS SS LMU U U UU Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 6 15 MATCH ROM Command M Reset device and send the Match ROM command for the current device Form M a single character command The Match ROM command is used to reset and re select the current device on the 1 Wire bus Once a device has been selected subsequent commands can operate on it without t
9. command is sent the HA7E will wake up process the command send the response and power down The 1 Wire bus can be left in a powered up or a powered down state while the HA7E is powered down While in power down mode the HA7E has a very low quiescent current requirement The HA7E can perform Search and Family search functions making it easy to acquire the unique 64 bit serial numbers of all connected devices Many sensor devices require that extra power be delivered during periods of data conversions DS1920 and DS1820 temperature sensors for example The HA7E automatically provides the extra current these devices require with a built in smart strong pull up Dallas Semiconductor iButtons which store data in TMEX Touch Memory File format can be read or written with simple ASCII commands The HA7E will automatically generate and check the CRC16 error checks from Touch Memory File records The HA7E supports analog digital and temperature 1 Wire devices and all Dallas Semiconductor iButtons 1 Wire and iButton are registered trademarks of Dallas Semiconductor TMEX is a trademark of Dallas Semiconductor eE SSS l O OU l l a O Ul U U UUU U U C al Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 1 15 Command List S SEARCH ROM Allows the HA7E to use a process of elimination to identify the 64 bit ROM codes of all slave devices on the bus s NEXT SEARCH ROM Identify the 64 bit ROM codes
10. ecord directive p is the page number of the record to be written data is a 0 to 28 byte hex string representing the data to write into the selected page See Chapter 7 of the Book of DS19xx iButton Standards from Dallas Semiconductor for a comprehensive discussion of the Touch Memory File Structure The U command will always write 28 bytes of data even if the user provides less than 28 bytes The application may require that the user write all 28 bytes each time This command will automatically set the continuation pointer to the next page this limits the use to files that have contiguous records The HA7E can only write to 1 Wire devices and iButtons in Touch Memory File Structure records However the user can directly communicate with any 1 Wire device or iButton using the block write read commands W The block commands support all device functions Example Write the record HA7 is Easy To USE into the file that contains page 21 hex of the DS1996 with ROM code EF00000003B7890C Command Response AEF00000003B7890C lt CR gt lt CR gt 121484137206973204561737920544F20555345 lt CR gt lt CR gt p 21 the page number of the file record to write to data data 484137206973204561737920544F20555345 HA7 is Easy To USE in ASCII hex Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 12 15 WRITE READ BLOCK Commands w Form Wb data lt CR gt Where b is byte cou
11. ehensive discussion of the search ROM function The Search ROM command selects the 1 Wire device that corresponds to the ROM code sent to the host last as a response Devices may also be selected with the A address M match ROM or F family search commands Once selected all commands will operate on the selected device until another device is selected Example Read the ROM codes of the first slave device on the bus Command Response S 7F0000000836A410 lt CR gt s NEXT SEARCH ROM Form s a single character command The Next Search ROM command must be used after the first search to find additional ROM codes This command can only be used after a S or s command for valid response This command can be sent repetitively until all 1 Wire device ROM codes are found The Next Search ROM command selects the 1 Wire device that corresponds to the ROM code sent to the host last as a response Devices may also be selected with the A address M match ROM or F family search commands Once selected all commands will operate on the selected device until another device is selected Example Read the ROM codes of the all slave device on the bus Command Response S 7F0000000836A410 lt CR gt A00000000B14E710 lt CR gt 800000000AE6A012 lt CR gt EA0000000AE5AF12 lt CR gt s s s s lt CR gt no more devices Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 P
12. have activity of interest See the individual device specifications from Dallas Semiconductor for details on the conditional search capability of a specific 1 Wire device The Conditional Search ROM command selects the 1 Wire device that corresponds to the ROM code sent to the host last as a response Devices may also be selected with the A address S search F family search and M match ROM commands Once selected all commands will operate on the selected device until another device is selected Example Search for all slave devices on the bus fulfilling the respective conditions for conditional search Note each 1 Wire device family may or may not support conditional search see the individual device specifications for details Command Response C 7F0000000836A410 lt CR gt c 0600000001C8BE12 lt CR gt c lt CR gt no more devices with alarms In the above example a D1820 DS1920 family code 10 had an alarm condition and a DS2407 family code 12 had an alarm condition pending No other devices had alarms pending See the individual device specifications for details on conditional alarm search capabilities Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 5 15 ADDRESS Select Command A ADDRESS Select Form Aa lt CR gt Where A is the command directive and a is the ADDRESS The Address command is used to select a device on the 1 Wire bus
13. he bus master always writes even when reading The bus master writes 1 time slots whenever it wishes to write a 1 bit or when it wishes to read a bit from a selected slave When reading a bit the response to a write 1 time slot may be either 0 or 1 depending on weather or not the slave device holds the bus low to indicate a 0 bit The block write read commands will send up to 32 bytes of 8 bits each onto the 1 Wire bus and record the slave response and send it back as a command response This is a very powerful and efficient technique for communicating with 1 Wire slaves Example Select the DS2407 with ROM code 2400000007377212 issue the Channel Access command and read the Channel Info Byte which contains the input latches output latches and sensed levels of the two I O lines PIOA PIOB Command Response A2400000007377212 lt CR gt 2400000007377212 lt CR gt WO4F5CFFFFF lt CR gt F5CFFF47 lt CR gt Note 4 bytes were written and 4 bytes were read The last byte written FF is a read byte corresponding to the reading of the Channel Info Byte in the DS2407 See the DS2407 specification from Dallas Semiconductor for more details on the operation of the DS2407 Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 13 15 POWER DOWN Command P 1 WIRE POWER DOWN Form P a single character command The Power Down command will cause the1 Wire bus voltage to be reduced to 0 volts
14. he need to select it again The HA7E will remember the ROM code of a selected device and automatically use it when necessary to re address the selected device without the users need to re send the ROM code ROM codes are determined with the S search M match ROM and F family search commands The Match ROM command resets and selects the current 1 Wire device and responds with the ROM code of that device Devices may also be selected with the F family search S search or M match ROM commands Once selected all commands will operate on the selected device until another device is selected Example Reset and re select the DS2407 currently addressed then read the channel info byte with the W command Command Response M 0600000001C8BE12 lt CR gt WO4F5FFFFFF lt CR gt F5FFFFA6 lt CR gt The channel info byte is A6 the last byte See the DS2407 specification from Dallas Semiconductor SESE SS SS ar Embedded Data Systems LLC 2019 Fortune Drive Lawrenceburg KY 40342 Phone Fax 502 859 5490 7 15 WRITE ONE READ BIT Command O WRITE ONE READ BIT and Z WRITE ZERO BIT COMMANDS Form O or Z single character commands The bit write read command is the lowest level 1 Wire command This command allows a single bit either zero 0 or one 1 to be read from the bus or a 1 to be written to the bus This function is provided to allow direct manipulation of 1 Wire devices and is n
15. hone Fax 502 859 5490 3 15 Family Search Command F FAMILY SEARCH f NEXT FAMILY SEARCH Form Fe Where F is the command directive and c is the family code Family search speeds the process of selecting a specific device on the 1 Wire bus if the user knows the family code In a network of many devices the user may wish to read for example the temperatures of all the DS1820 based sensors The family search command F10 can be used to locate the first sensor the temperature can be read with the W command Subsequent temperature sensors can be selected with the f command and read with the W command until all temperatures have been taken indicated by a CR only response or a ROM code with a different family code response The Family Search command selects the 1 Wire device that corresponds to the ROM code sent to the host last as a response Devices may also be selected with the A address or S search commands Once selected all commands will operate on the selected device until another device is selected Example Search for all DS1820 DS1920 temperature sensor devices on the bus family code 10 and read the temperature data with the W command Note After the first selection of a device with the desired family code subsequent searches must be made with the f command until a lt CR gt only is returned indicating that all have been found Command Response F10 family search 7F
16. nt to write and data is the block to write onto the 1 Wire bus 1 32 bytes The write read block commands are very similar to the write read bit command The block commands performs the bit write read functions on blocks of data up to 32 bytes long The block write read commands are the most powerful of the 1 Wire commands provided by the HA7E These commands allow blocks of data either zeros 0 or ones 1 to be written or read on the bus This function is provided to allow direct manipulation of 1 Wire devices and can provide interface to all 1 Wire device functions On a 1 Wire bus the bus master HA7E writes a one 1 by setting the bus voltage low for a short time See Chapter 1 of the Book of DS19xx iButton Standards from Dallas Semiconductor for details A bus master writes a zero 0 by setting the bus voltage low for a longer time When a slave device needs to communicate a one 1 bit it simply does nothing during the bus master write of a one 1 time slot When a slave device needs to communicate a zero 0 bit it holds the bus master write one 1 time slot low for the longer time indicative of a zero 0 time slot This allows the slave device to communicate both zero and one bits without the need to drive the bus The 1 Wire bus master does the bus driving A slave device only needs to hold the bus low during time slots that it wishes to communicate a zero 0 bit value The W commands is both a write block and read block command T
17. ot normally required On a 1 Wire bus the bus master HA7E writes a one 1 by setting the bus voltage low for a short time See Chapter 1 of the Book of DS19xx iButton Standards from Dallas Semiconductor for details A bus master writes a zero 0 by setting the bus voltage low for a longer time When a slave device needs to communicate a one 1 bit it simply does nothing during the bus master write of a one 1 time slot When a slave device needs to communicate a zero 0 bit it holds the bus master write one 1 time slot low for the longer time indicative of a zero 0 time slot This allows the slave device to communicate both zero and one bits without the need to drive the bus The 1 Wire bus master does the bus driving A slave device only needs to hold the bus low during time slots that it wishes to communicate a zero 0 bit value The only condition under which the slave drives the bus is during reset presence The O command is both a write bit and read bit command When the bus master is writing bits both O and z commands apply When the bus master is reading bits only the O command applies When reading a bit the response to a O command may be either 0 or 1 depending on weather or not the slave device holds the bus low to indicate a O bit The block command W performs this same function on blocks of data Example Write a zero 0 on the bus Command Response write a 0 bit
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