USB-DIO-16H - ACCES I/O Products, Inc.
Contents
1. ciii inei dete Iusta eda eessen n epa eege ee icti etus 15 Appendix A Theory of Operation nennen entretenir nnns innen 17 eim eet eet eee 17 Input inei te inei idu ie tun fita state Ide age stat bette dacs tats teeta utum beara dae 18 Paired Operation iid eee Pd ceat bate ger om Pase run ate Ped peter a Po een cebat fees Popes 18 Warning about bus CONTENTION eene nnne Ennan Enna nnne nnns 19 Appendix B Proposed I O Negotiation Algorithms cccccceeceeceee cece eeeeaeeeeneeseaeeesaeeeeaaeeenees 20 Hard Coded Embedded Confguratton sess 21 Handshaking Used Known Slave enne enne 23 Handshaking Used Known Master 25 Customer e E EE 26 4 USB DIO 16H User Manual Chapter 1 Introduction This USB based Data Acquisition Module is an ideal solution for adding portable easy to install high speed digital input output to any computer with a USB port The unit is a USB 2 0 high speed device and requires a USB 2 0 port to function Features e 16 high speed digital I O lines featuring continuous throughput of 16MB s Capable of 80MB s bursts Flexible internal or external synchronous clocking and handshaking capabilities 18 additional digital I O lines All output lines buffered with 24mA sink source current capabilities Standard 68 pin High Density connector Custom high speed function driver PC 104 module size and mounting compatibility Small 4 x 4 x 1 25 rugged industrial enclosure Min2. Input voltage Input current Output voltage Output current Internal Clock Frequency Range External Clock Frequency Data FIFOs Width Depth Environmental Operating Temperature Storage Temperature Humidity Board Dimensions Box Dimension Power Power required Auxiliary power output 18 programmable as inputs or outputs as 4 Ports A D Logic low 0 5 to 0 8 VDC Logic high 2 0 to 5 0 VDC 20UA max Logic low 0 44 VDC max Logic high 4 4 VDC min Logic low 24mA max sink Logic high 24mA max source 1k 40MHz 40 MHz maximum 16 bit USB DIO 16H 128 kByte USB DIO 16A 8 kByte USB DI16A 8 kByte USB DO16A 8 kByte 0 to 70 C optional 40 to 85 C 40 to 105 C 5 to 95 RH without condensation PC 104 format 3 550 by 3 775 and mounting holes 4 00 x 4 00 x 1 25 inches 5V at 100mA with no load typical 5VDC via 0 5A resettable fuse at connector jumper selectable 3 3VDC via 0 5A resettable fuse with LVTTL Option 15 USB DIO 16H User Manual Power Modes USB port 5VDC provided via USB bus up to 500mA External supply Optional external power adaptor 9VDC through DC power jack and on board regulator to produce 5VDC Factors that affect the amount of current required by this module include any power drawn from the auxiliary 5VDC through the resettable fuse as well as any digital outputs that are wired to source current to external circuits where the othe
3. FUSED 5VDC 3 3VDC LVTTL Option USB DO16A or USB DIO 16x IN OUTPUT MODE 90 oo USB DI16A or USB DIO 16x IN INPUT MODE C THESE BUFFERS ARE AVAILABLE IN EITHER 5V TTL OR 3 3V LVTTL AS A FACTORY INSTALLED OPTION LV Figure 1 1 Block Diagram High Speed Digital UO There is one 16 bit high speed Digital I O bus DATA 1 00 to DATA 1 015 available on this board This bus can be configured for either inputs outputs depending on the model ordered These ports can also be tri stated Each DIO line is buffered and capable of sourcing 24mA or sinking 24mA Be sure to consult the Power section for total power limitations before operation By default the DIO lines are pulled up with a 10KQ resistor to 5V Digital UO There are 18 additional Digital UO lines Port A Port B Port C and Port D available on this board Each port can be configured for either input or output however Port C and Port D are always configured in opposite directions of each other These ports can also all be tri stated Port A is an 8 bit Port Port B is a 4 bit Port and Ports C and D are each 3 bits Each DIO line is buffered and capable of sourcing sinking 24mA Be sure to consult the Power section for total power limitations before operation By default the DIO lines are pulled up with a 10KO resistor to 5V 6 USB DIO 16H User Manual Ordering Guide USB DI16A 16 High Speed Digital Inputs ONLY w 4K word FIFO and 18 standard I Os USB DO16A 16 High Speed D
4. be tristated All UO lines at the connector will have 5V from 10k ohm pull ups Using DIO Configure set PORT A as an input and untristate ONLY port A The direction settings for ports B D don t matter as they will remain tristated Similarly the initial output values are also irrelevant Use DIO Reaa8 or DIO_ReadaAll to read the bits from Input Port A Remember the state of all the bits as they will be used later Check the value you read from Port A to see if bit 7 is low or zero Using bit 7 here is arbitrary you could write your software to use any bit or even several bits This algorithm uses bit 7 to indicate a master has asserted itself If bit 7 is NOT LOW the connected master has not yet gotten around to presenting its handshaking information on these pins Follow the NO branch of the flowchart Please note for enhanced error detection it would be useful to detect a situation where Bit 7 was high but one or more bits on the port were low and flag this as an error condition If bit 7 IS LOW it indicates the connected master device has presented its handshaking configuration on the pins and we can continue to the YES branch of the flowchart a In areal world environment it is unwise to code loops that may never exit This loop is one such case If the cable has become disconnected your software would forever wait for Port A7 to go low and it never would We therefore recommend either timing out from this loop or g
5. refer to the setup program installed from the CD provided with the board There are two user selectable hardware options available One is VUSB vs VEXT which selects between USB powered or externally powered The other is fused 5V output on I O connector pin 34 or NC no connect Figure 3 1 Option Selection Map 9 USB DIO 16H User Manual USB Connector P1 The USB connector available via the outside of the enclosure is a Type B and mates with the six foot cable provided The USB port provides communication signals along with 5 VDC power The board can be powered from the USB port or an external power supply can be used Embedded USB Connector P4 In applications where the OEM board only no enclosure version of this board is used it may be desirable to use the miniature USB connector onboard which is next to and in parallel with the Type B connector LED The LED on the front of the enclosure is used to indicate power and data transmissions When the LED is in an illuminated steady green state this signifies that the board is successfully connected to the computer and has been detected and configured by the operating system When the LED flashes continuously this signifies that there is data being transmitted over the USB bus FUSED 5V The fused 5V jumper is located near J1 When installed in the 5V position the fused 5V will become available on pin 34 of J1 The fuse is rated at 500mA and is self resetting If the jump
6. that prompt service and support will be available All equipment originally manufactured by ACCES which is found to be defective will be repaired or replaced subject to the following considerations Terms and Conditions If a unit is suspected of failure contact ACCES Customer Service department Be prepared to give the unit model number serial number and a description of the failure symptom s We may suggest some simple tests to confirm the failure We will assign a Return Material Authorization RMA number which must appear on the outer label of the return package All units components should be properly packed for handling and returned with freight prepaid to the ACCES designated Service Center and will be returned to the customer s user s site freight prepaid and invoiced Coverage First Three Years Returned unit part will be repaired and or replaced at ACCES option with no charge for labor or parts not excluded by warranty Warranty commences with equipment shipment Following Years Throughout your equipment s lifetime ACCES stands ready to provide on site or in plant service at reasonable rates similar to those of other manufacturers in the industry Equipment Not Manufactured by ACCES Equipment provided but not manufactured by ACCES is warranted and will be repaired according to the terms and conditions of the respective equipment manufacturer s warranty General Under this Warranty liability of ACCES is limited to repla
7. you should understand the available and sometimes necessary handshaking signals on the connector associated with all that power You may wish to refer to the Block Diagram while reading this appendix In general the entire high speed bus on any given unit can be treated as a single FIFO Let s discuss only the output board or the I O board being used in output mode for a moment Output Four signals accompany the data on the output board TX ACK TX FE TX EN and TX CLK It is convenient to think of these four signals in two pairs block and per word handshaking lines TX FE and TX EN are the block handshaking lines TX FE indicates the FIFO is Empty it goes high when the FIFO is empty TX EN indicates the receiving device wants to stop a moment we ll get into why it might want to stop when we discuss the receive mode Note pulling TX EN LOW indicates GO You need to raise the line HIGH to STOP transmission TX CLK and TX ACK are the per word handshaking lines TX CLK tells the FIFO when to transmit the next data word Specifically each rising edge of TX CLK will assert the next word of data out of the FIFO TX ACK tells the receiving board that the FIFO has successfully asserted a word of data and it is ready to be read These two signals are almost the same TX ACK is simply a slightly delayed version of TX CLK to ensure the data out of the FIFO has had time to stabilize before the receiver tries to read
8. Empty active high When TX FE is HIGH the FIFO is empty and further data reads from the output are inhibited When TX FE is low the FIFO is not empty TX FE is synchronized to TX ACK RX CLK External Receive Clock When RX EN is LOW data is written into the FIFO on a LOW to HIGH transition of RX CLK if the FIFO is not full This signal is used when providing an external clock and not using the internal clock on board which is programmable from 1K 40MHz TX ACK Transmit Acknowledge Clock When TX ACK transitions from LOW to HIGH data can be read from the board TX ACK is the delayed clock used to read data out of the FIFO RX AF Receive Almost Full Flag active high When RX AF is HIGH the FIFO is 127 words from full TX EN Transmit Enable active low When TX EN is LOW data is read from the FIFO on every LOW to HIGH transition of TX CLK or from the internal clock on board When TX EN is HIGH the output register holds the previous data Data will not be read from the FIFO if the TX FE is HIGH RX ACK Receive Acknowledge Clock When RX ACK transitions from LOW to HIGH data has been read into the board RX ACK is the delayed clock used to read data into the FIFO TX CLK External Transmit Clock When TX EN is LOW data is read from the FIFO on a LOW to HIGH transition of TX CLK if the FIFO is not empty This signal is used when providing an external clock and not using the internal clock on
9. appropriate for your operating system Substitute the appropriate drive letter for your drive where you see D in the examples below WIN98 Me 2000 XP 2003 a Place the CD into your CD ROM drive b The CD should automatically run the install program If the install program does not run click START RUN and type SJUA click OK or press zl C Follow the on screen prompts to install the software for this board LINUX a Please refer to linux htm on the CD ROM for information on installing under Linux Hardware Installation Please install the software package before plugging the hardware into the system The board can be installed in any USB 2 0 port Please refer to the USB I O Quick Start Guide which can be found on the CD for specific quick steps to complete the hardware and software installation NOTES ABOUT HAND SHAKING In order to transmit data you MUST ground the pulled up TX EN Transmit Enable signal at PIN 19 In order to receive data you MUST ground the pulled up RX EN Receive Enable signal at PIN 17 Please note if connecting two USB DIO 16H family devices together with a standard 1 to 1 cable these signals are correctly connected to RX AF Receive FIFO Almost Full and TX FE Transmit FIFO Empty respectively If your application supports this kind of handshaking connect those signals instead of simply grounding these pins 8 USB DIO 16H User Manual Chapter 3 Hardware Details Option Selection You may also
10. bility to detect cable breaks etc So to finish if your reading of Port A tells you what inputs and outputs the master is configuring simply configure your ports to be the opposite if bit A2 is low indicating Port C is an output make sure you configure the slave s Port C as an input The unit is now configured and ready for use Any combination of DIO Readxxx and DIO Writexxx functions may be used to access the slow digital bits and the DIO Streamxxx functions can be used to perform fast buffered I O 23 USB DIO 16H User Manual Handshaking Used Known Master 1 Power ON Configure port directions Write initial values Port A Input Un tristate only A 3 Read Port A T e Collision 4 1 Error Notify User Assert A7 Low amp Assert I O direction on A0 A6 Un tristate all ports 6 Use as desired 24 USB DIO 16H User Manual Handshaking Used Known Master At this point the unit will be tristated All UO lines at the connector will have 45V from 10k ohm pull ups Using DIO Configure set PORT A as an input and untristate ONLY port A The direction settings for ports B D don t matter as they will remain tristated Similarly the initial output values are also irrelevant Use DIO_Read8 or DIO ReadAIl to read the bits from Input Port A Remember the state of all the bits as they will be used later Check the value you read from Port A to see if bit 7 is low or zero Using bit 7 here is arbitrary you c
11. board which is programmable from 1K 40MHz GND N A Ground DIO AO through A7 1 0 Port A Digital UO Bit 0 through Bit 7 all pulled up through 10K ohms to 5V DIO BO through B3 1 0 Port B Digital UO Bit 0 through Bit 3 all pulled up through 10K ohms to 5V DIO CO through C2 1 0 Port C Digital UO Bit 0 through Bit 2 all pulled up through 10K ohms to 5V The direction of this port is the inverse of Port D s direction DOI DO through D2 O I Port D Digital O I Bit 0 through Bit 2 all pulled up through 10K ohms to 5V The direction of this port is the inverse of Port C s direction which is why we named them O I Bits FREQUENCY OUT Optional Signal Reserved FUSED 5V O Jumper Selectable 500mA Fused 5V This is an output ONLY Do not apply 5V to this pin N C Not Connected TABLE 6 2 Detailed Pin Descriptions 14 USB DIO 16H User Manual Chapter 7 Specifications TTL High Speed Digital I O s LVTTL Optional Lines Continuous Throughput Input voltage Input current Output voltage Output current 16 programmable as all inputs or all outputs 16A or 16H only 8MHz or 16MB s maximum Logic low 0 5 to 40 8 VDC Logic high 2 0 to 5 0 VDC 20UA max Logic low 0 44 VDC max Logic high 4 4 VDC min Logic low 24 mA max sink Logic high 24 mA max source TTL Standard Digital I O s LVTTL Optional Lines
12. cing repairing or issuing credit at ACCES discretion for any products which are proved to be defective during the warranty period In no case is ACCES liable for consequential or special damage arriving from use or misuse of our product The customer is responsible for all charges caused by modifications or additions to ACCES equipment not approved in writing by ACCES or if in ACCES opinion the equipment has been subjected to abnormal use Abnormal use for purposes of this warranty is defined as any use to which the equipment is exposed other than that use specified or intended as evidenced by purchase or sales representation Other than the above no other warranty expressed or implied shall apply to any and all such equipment furnished or sold by ACCES 3 USB DIO 16H User Manual TABLE OF CONTENTS Chapter 1 Introduction A 5 FeatUtes 5o oce e Dsum ee T ee 5 Applications E 5 Functional Description 2o Pro pependit Pi 5 Figure 1 1 Block Diagram Roe nme mma 6 High Speed Wale UCL EE 6 hnc EE 6 Ordering Guide 3 S ge da dte HERE ar edet reda e Pet cea e nee Tee es 7 Model Options und Eee Let e te Ine Heo aa Le de dub e Dee Ee eod eben duce 7 Included with your board nnne nn en nennen tnr nennen nennen 7 Optional accessories e iue dut es b e c ERE HEEL Bep e ERE ca dee deeded anes 7 Chapter 2 Installation 2 a a ERE n Euge CERS 8 Software CD Installation eene nennen nnns tres enne nnns nennen 8 Ha
13. ded Configuration 1 2 Power On at this point the unit will be tristated All I O lines at the connector will have 5V from 10k ohm pullups Using DIO Configure set PORT A B C and D for their desired directions remembering that PORT C and D must always be opposed select the initial values for any ports configured as outputs and untristate all the ports Remember this mode requires either that the software for the connected device be written to match these port directions that the connected device is simply hardwired to match these port directions or that you re using a cable that doesn t make these connections If you connect an output on this device to an output from your connected device you may destroy one or both devices and will certainly void your warranty Done When you re embedded or hardcoded there aren t many steps needed The unit is now configured and ready for use Any combination of DIO Readxxx and DIO Writexxx functions may be used to access the slow digital bits and the DIO Streamxxx functions can be used to perform fast buffered I O 21 USB DIO 16H User Manual Handshaking Used Known Slave 1 Power ON Configure Port A as input 2 Enable only Port A Contigure Port Directions 5 to match A0 A6 un tristate all ports 6 Use as desired 22 Timeout or allow user abort NH E d ULP PPP USB DIO 16H User Manual Handshaking Used Known Slave At this point the unit will
14. e USB board This driver will allow you to determine how many supported USB devices are currently installed and each device s type This information is returned as a Vendor ID VID Product ID PID and Device Index The VID for all four models is Ox1605 and the PID is unique for each model as follows USB DIO 16H PID Ox800C USB DI16A PID Ox800D USB DO16A PID Ox800E USB DIO 16A PID Ox800F Using the VID and PID as demonstrated in our sample programs will allow you to determine how many of these devices are attached to your system and the system assigned Device Index for each of those devices If you have more than one of any given PID you may encounter the need to tell them apart reliably as the system assigned Device Index is a plug and play value that changes as devices are plugged into and removed from your system In order to enable you to reliably tell devices with the same VID PID apart we have implemented a user accessible region of the onboard EEPROM Refer to the Software Reference Manual for more information about the CustomEEPROMRead and CustomEEPROMWrite function for details In general you can simply write a unique value to a byte of EEPROM then your software can track changes to the Device Index units by this value In addition the user accessible EEPROM is hundreds of bytes long enabling numerous optional functionality of your choice See the Software Reference Manual install
15. e it is all in one DIO Configure command its most efficient to select the direction of the ports write initial values to all of them and untristate all of them in this single step The unit is now configured and ready for use Any combination of DIO Readxxx and DIO Writexxx functions may be used to access the slow digital bits and the DIO Streamxxx functions can be used to perform fast buffered I O USB DIO16A User Manual Customer Comments If you experience any problems with this manual or just want to give us some feedback please email us at manuals accesio com Please detail any errors you find and include your mailing address so that we can send you any manual updates PO ZXCc CES I O PRODUCTS INC 10623 Roselle Street San Diego CA 92121 Tel 858 550 9559 FAX 858 550 7322 www accesio com 26 USB DIO16A User Manual
16. ed on your system along with the board support package for more information 11 USB DIO 16H User Manual Chapter 5 Programming The driver software provided with the board uses a 32 bit dll front end compatible with any Windows programming language Samples provided in Borland C Builder Borland Delphi Microsoft Visual Basic and Microsoft Visual C demonstrate use of the driver Many functions are provided by the driver in Windows For detailed information on each function refer to the PDF Software Reference Manual located in the Win32 directory for this board 12 USB DIO 16H User Manual Chapter 6 Connector Pin Assignments The I O connector is a 68 pin Type 2 SCSI female right angle type with quick release one touch locking latches which protrudes through a cutout in the module s enclosure 34 1 Be 35 Pin Signal Name Pin Signal Name 34 FUSED 5V jumper selected 68 GND TABLE 6 1 Connector Pin Assignments 13 USB DIO 16H User Manual Name UO Description DATA I O 0 through 15 1 0 16 Bit Data Bus Input Output Bit 0 through 15 all pulled up through 10K ohms to 5V RX EN Receive Enable active low When RX EN is LOW data is written into the FIFO on every LOW to HIGH transition of either RX CLK or from the internal clock on board When RX EN is HIGH the FIFO holds the previous data Data will not be written into the FIFO if it is full TX FE Transmit FIFO
17. er is installed in the NC position or is not installed pin 34 is a no connect DC Power Jack Optional Please note not all boards will contain this option This is an option for high current applications when more current is needed than what your computer can provide on the USB port typically 500 mA The DC jack has a 2 00mm post on board and is designed to be used with the 9 VDC AC DC external power supply that ships with this option The voltage regulator on board regulates the 9 VDC and provides 5 VDC to the onboard circuitry When using external power switch the jumper located near the USB connector to VEXT otherwise when the jumper is in the VUSB position current is drawn from the USB port please consult the option selection map for a visual reference If the board will be ordered as an OEM P option board only with external power then the power input will be reconfigured by removing the voltage regulator to prevent damage during shipment and while handling such that the external power supply should then provide a regulated 5 VDC to the power jack instead of the standard 9 VDC 68 PIN UO Connector J1 The I O is accessed via a 68 pin female SCSI Pin in Socket type connector with one touch lock latches Detailed pin assignments are listed in chapter 6 as well as a handy reference of pin functions printed on the enclosure label 10 USB DIO 16H User Manual Chapter 4 USB Address Information Use the provided driver to access th
18. iature USB connector for embedded applications Applications Digital Imaging e Embedded data acquisition e Data Transfer e Education Laboratory Functional Description This product is a USB based digital board with16 high speed digital inputs outputs capable of up to 8MHz 16MegaByte continuous scanning and up to 40MHz 80MegaByte bursts Four model versions are available an input output unit USB DIO 164 an input only unit USB DI16A an output only unit USB DO1 64 all with 4k word FIFOs and an input output unit with expanded 64k word FIFO USB DIO 16H The 16 high speed lines are TTL compatible digital inputs outputs with high current capabilities The programmable clock facilitates capability of 1k 40MHz transfers or the user may choose to use their own external clock All clock signals are provided on the connector and are synchronous In addition to the 16 high speed inputs outputs there are 18 standard digital UO channels configurable as 4 separate ports for input or output Power is supplied to the board via the USB cable for higher current capabilities external 9V AC DC power adapter may be used The I O wiring connections for this unit are via an industry standard 68 pin SCSI connector For external circuits fused 5VDC see note power is available at the connector based on a hardware jumper selection made by the user This resettable fuse is rated at 0 5A Note Anywhere 5VDC is referred to in this manual with the excep
19. igital Outputs ONLY w 4K word FIFO and 18 standard I Os USB DIO 16A 16 High Speed Digital Inputs OR Outputs w 4K word FIFO and 18 standard I Os USB DIO 16H 16 High Speed Digital Inputs OR Outputs with 64K word FIFO and 18 standard I Os Model Options e LV LVTTL for 3 3V applications P External AC DC adapter power jack regulator installed OEM Board only no enclosure DIN DIN rail mounting provision T Extended Temperature Operation 40 to 85 C S0x x special number designator examples include 16K FIFO 32K FIFO 64K FIFO conformal coating etc Included with your board The following components are included with your shipment Please take time now to ensure that no items are damaged or missing USB Module unit installed in labeled enclosure 6 USB cable Software Master CD PDF user manual installed with product package Printed USB I O Quick Start Guide mop Optional accessories e C68PS18L 68 Pin SCSI 18 shielded cable with one touch latches e STB 68 Screw Terminal Board mounted on standoffs e CUSB EMB 6 6 USB Cable with type A connector to mini USB connector for embedded applications mates with P4 on the board e MP104 DIN DIN rail mounting provision 7 USB DIO 16H User Manual Chapter 2 Installation Software CD Installation The software provided with this board is contained on one CD and must be installed onto your hard disk prior to use To do this perform the following steps as
20. it TX CLK as shown on the block diagram can come from two sources TX CLK provided by the user to pin 20 on the connector or the internal oscillator If the internal oscillator is selected TX ACK takes on even more importance as the external device must synchronize to this signal Theoretically the outside device could generate its own TX ACK equivalent by simply waiting a moment after sending TX CLK before reading the data however TX ACK will not occur if TX EN is disabled high Because of these complexities it is best to design your device to use TX ACK as the read data now signal To recap if TX FE is LOW data is available If TX EN is LOW subsequently causing a TX CLK will assert data and cause a TX ACK indicating the data has finished being asserted and is safe to read This process will continue until TX FE goes high or TX EN is asserted high indicating no more data is available or the receiver needs to stop for some reason The receiver unit has a similar and functionally correlated set of handshaking signals associated with its high speed bus 17 USB DIO 16H User Manual Input The four handshaking lines on the input board or the I O board in input mode are RX_ACK RX AF RX CLK and RX EN It is convenient to think of these four signals in two pairs block and per word handshaking RX CLK and RX ACK are the per word handshaking lines RX CLK tells the receiving FIFO to latch in the data currentl
21. its to work together using an off the shelf one to one cable so no gender changer or null modem interface is necessary The I O unit contains all the circuitry needed to adapt its handshaking pinout to the current direction of its I O bus eliminating all the hassles of common equipment The block diagram shows a typical application example and indicates the pairing of handshaking signals TX ACK can be used to supply the RX_CLK on pin 18 of the connector if desired or you can use the internal HX CLK source TX FE supplies the RX EN signal when the transmit FIFO is empty the receiver card stops paying attention to its RX CLK even if it s using internal Similarly RX AF is used as TX EN whereby the transmit board ignores its TX CLK signal when the receiver FIFO is almost full And last the RX ACK signal can be used to supply TX CLK on pin 20 of the connector or TX CLK can be generated internally 18 USB DIO 16H User Manual Warning about bus contention Please note you should never connect an output unit to an output unit nor an input unit to an input unit to avoid bus contention and potentially destroying your equipment Even when used as inputs the bus has handshaking pins configured as output so these handshaking pins would be in a contention situation Similarly if you re using the selectable I O unit avoid ever having both sides of the cable configured as input or output at the same time The same warning a
22. iving the user the option to abort the detection process or both Using the DIO Configure API you can select the direction for all the I O ports to match the value you read on Ports AO AA4 write initial values to all of them any port selected for input will ignore its configured output value and untristate all the ports A word about matching the value the master will assert one bit for each port Port A is an output by definition because the master is using it to communicate the other bits to us This leaves Port B Port C Port D and the fast DI O Port as possible direction information the master needs to communicate to us Because Port C and Port D are guaranteed to always be opposite direction you could skip using a pin for Port D If you are not using the unit with the fast port having selectable direction you could skip that as well For the sake of this algorithm we recommend not to skip any ports Port AO indicates the direction of Port A bit A1 is associated with Port B s direction bit A2 will indicate Port C bit A3 is for Port D and bit A4 is the direction of the fast DI O bus Doing so allows you to code more error detection into your algorithm if bit A2 is not the opposite of A3 there s an error If AO does not indicate the master is using it as an output its another error etc It is also for this reason we recommend using low as output Doing so guarantees that bit AO should be low as well as bit A7 furthering your a
23. maximum flexibility and device I O capability Digital Port A can be used to provide basic handshaking or it can be used as an 8 bit output or 8 bit input port as your specific application requires The following pages will describe several possible ways to initialize the ports We ll first cover the typical and most common embedded case where Port A is not being used as a handshaking port and all configuration is hard coded into the controlling software Then wel consider three alternate situations and algorithms for handling them When reading the following flowcharts please note the small number located in each box and refer to the numbered paragraphs following the four flowcharts for detailed information about each step Several important concepts will be useful before reading these flowcharts Master means a unit that has been designated as controlling the direction of the ports on both itself and any device connected to it Slave means a unit that only sets the direction of its ports based on the directions of a connected Master unit Port A is the 8 bit digital input output port we re using to communicate this handshaking information Why port A Because only it can be enabled while leaving all the other ports tristated 20 USB DIO 16H User Manual Hard Coded Embedded Configuration Power On Select port directions a Write initial values Un tristate all ports 3 Use as desired Hard Coded Embed
24. ould write your software to use any bit or even several bits This algorithm uses bit 7 to indicate a master has asserted itself If any bit is LOW move to the NO branch of the flowchart if all bits on input port A read HIGH move to the YES branch of the flowchart Since this device is running as a dedicated master seeing bit 7 low means something has gone horribly wrong and you need to abort the process before you set this port as an output For better error detection you should check all the bits to make sure none of them are asserted low any bits that read low are either grounded at the connector or broken in either case you should abort before using the unit Now that you ve detected no collision on Port A you should change Port A to output and write the handshaking pattern We re using the same bit pattern from the previous flowchart Port A bit 0 indicates the direction of port A and LOW means output So bit 0 should always be asserted low under this algorithm Your software can do it however you d like Bit A1 will reflect port B s direction A2 Port C A3 Port D and A4 the fast DI O bus Remember that port C and D must always be configured for opposite directions and if you attempt to set C and D the same way C will be set to the opposite of D that is the configuration for port C is ignored Additionally set the bit 7 Master bit low to indicate you ve completed asserting your handshaking pattern And sinc
25. pplies to the slow speed digital I O ports shown on the block diagram the next section will discuss methods of avoiding this kind of contention 19 USB DIO 16H User Manual Appendix B Proposed I O Negotiation Algorithms NOTICE For most customers there will be no need to allow the end user to select I O directions you will simply write your software to hard code your digital ports into specific directions at initialization and know confidently that the software written for the connecting device will safely configure He ports in a compatible manner However during development in the lab or for those customer s that cannot know how the end user will desire the ports to be configured it may be useful to explore implementing a handshaking protocol to minimize the opportunity for error In any application where two flexible devices are going to be connected together it is important that both devices are configured such that no output drivers are attempting to drive another devices output pins That is outputs on one device must only be connected to inputs on the other device Because this module is capable of flexibly selecting the input vs output direction of its various digital ports at run time some sort of handshaking protocol may be useful depending on how thoroughly hard coded you wish to make your software application This USB module includes hardware to support such a protocol without requiring its use this provides the
26. r side of the load is tied to ground return Any digital outputs wired to sink current to external loads will not necessarily increase the current drawn by the module unless the positive side of the load is fed from the auxiliary 5VDC previously mentioned If using more than a total of 500mA use optional 9 VDC on board voltage regulator outputs 5 VDC to card external power supply and remove VUSB jumper and place jumper on VEXT Then plug in external power before plugging into USB port This option will give you a total of 1000mA available If using the OEM board with the power option OEM P then use a regulated 5 VDC external supply as the on board regulator will not be installed USB 2 0 spec defines a device in terms of a unit load A unit load is defined to be 100mA Devices drawing an absolute maximum of one unit load are considered to be low powered and devices drawing an absolute maximum of five unit loads are considered to be high powered Because this spec is not strictly adhered to it is best to verify the USB port s power capabilities before operation This card according to the USB 2 0 spec is a high powered device An optional external power supply can be ordered if the USB port cannot support high powered devices 16 USB DIO 16H User Manual Appendix A Theory of Operation Unlike common 8255 based digital I O this unit provides a true synchronous high speed buffered digital bus What does this mean for you Well
27. rdware Installation 5 cernere eee ep ee De ee e re ea dee d bee ed Rena ket bh 8 NOTES ABOUT HAND GHAKING sse ener ennt sn tene inneren inne nnen nnt 8 Chapter 3 Hardware Details ssssssssssssssssssese eee tneren nennen innen nentes nnns nennen ns 9 Option Selection iioun x Rim e ue du ma Pup red od nee a tre Pee co Die da ee even i 9 Figure 3 1 Option Selection Map 9 USB Connector P1 inedite Eee e ee ben dl Do Oa a do an REI ER de eod 10 Embedded USB Connector DA 10 LED inpet citet utet vti Us teet ea ete e HEU E eta te 10 DG Power Jack Optional inne d meh e Der td re n niet ed D RUE Weide 10 68 PIN VO Connector Ch EE 10 Chapter 4 USB Address Information ssssssssssssssssssseeeee eee nennen 11 Chapter 5 Programming cei ete ee EEN geed eeh ve 12 Chapter 6 Connector Pin Assignments nnne enne 13 TABLE 6 1 Connector Pin Assignments sesssssssssssseseeee ener enne 13 TABLE 6 2 Detailed Pin Descriptions esistente nnne enne 14 Chapter 7 Specifications eese nnne nennt inttr inneren rinse nennen 15 TTL High Speed Digital I O s LVTTL Optional 15 TTL Standard Digital l O s LVTTL Optional 15 Internal Clock diei eU Een faic vie de Pede Pete uat e Poste pide fede d cds 15 Data FIFOS se EE 15 Environmental i idu icit Ite ten Ire taie im Peter eut em ege enee eg etus 15 POWOL
28. tion of USB power required can be substituted with 3 3VDC for the LVTTL option Pull ups to 5VDC on the board assure that I O lines are at a known state at power up until the board is initialized by system software A type B USB connector is used on all models which features a high retention design that complies with the class 1 Div II minimum withdrawal requirement of over 3 pounds of force 5 USB DIO 16H User Manual This connector has an orange color coded insulator to differentiate it from standard USB connectors The complete unit is designed for use in rugged industrial environments but is compact enough to fit nicely onto any desk or testing station The board is PC 104 sized 3 550 by 3 775 inches with mounting capability and ships standard inside a steel powder coated enclosure with an INTERNAL OSC EXT SELECT RECTION SELECTABLE ON USB Internal o g MB 7 Programmable Oscillator or External High Speed USB 2 0 Bus Lj F1 D I ei S z A Cypress A k HA H FX2 NV a b EM O o _ HE x a Internal Hd H ZN Programmable H o Oscillator o HO or External EI E d B INTERNAL OSC EXT SELECT E El E rI Es PD P BA BM EA Lj PORT DIRECTION SELECTS H E PORT DIRECTION SELECTS 2 E FUSED 5VDC 3 3VDC LVTTL Option
29. y on the bus pins RX ACK tells the transmitting board that the data has been successfully latched Again RX_ACK is simply a slightly delayed form of RX_CLK to ensure the FIFO has had time to digest the information RX AF and RX EN are the block handshaking lines RX AF indicates the receive board s FIFO is almost full This line will usually be low but if the digital bus data rate exceeds the USB bus and or computer system s ability to drain the FIFO the FIFO may begin to fill This line will go HIGH to indicate slow down This is why the receiving board may need to indicate Stop to the transmitting board Conversely RX EN indicates to the receiver board that the source of data needs to pause a moment If the transmitter were supplying the clock it could simply pause the clock but if the receive card is using an internal clock RX EN tells the receiver when to pause that clock Please note RX AF is asserted well before the FIFO actually fills giving your circuitry time to respond to the signal without losing data As mentioned briefly and in identical fashion to the TX CLK RX CLK can be supplied either from a pin on the connector or from onboard oscillator To recap if RX EN is LOW the receiver will pay attention to RX_CLK rising edges by latching in data then indicating success by asserting RX ACK If the receive FIFO begins to fill the receiver will assert RX AF Paired Operation We ve carefully designed these un
30. ya ACCES Lp PRODUCTS INC 10623 Roselle Street San Diego CA 92121 e 858 550 9559 ax 858 550 7322 contactus accesio com e www accesio com USB 16 CHANNEL HIGH SPEED DIGITAL INPUT OUTPUT MODULE MODELS USB DIO 16H USB DIO 16A USB DI16A USB DO16A USER MANUAL MUSB DIO 16H B1d Notice The information in this document is provided for reference only ACCES does not assume any liability arising out of the application or use of the information or products described herein This document may contain or reference information and products protected by copyrights or patents and does not convey any license under the patent rights of ACCES nor the rights of others IBM PC PC XT and PC AT are registered trademarks of the International Business Machines Corporation Printed in USA Copyright 2008 by ACCES I O Products Inc 10623 Roselle Street San Diego CA 92121 All rights reserved WARNING ALWAYS CONNECT AND DISCONNECT YOUR FIELD CABLING WITH THE COMPUTER POWER OFF ALWAYS TURN COMPUTER POWER OFF BEFORE INSTALLING A BOARD CONNECTING AND DISCONNECTING CABLES OR INSTALLING BOARDS INTO A SYSTEM WITH THE COMPUTER OR FIELD POWER ON MAY CAUSE DAMAGE TO THE I O BOARD AND WILL VOID ALL WARRANTIES IMPLIED OR EXPRESSED 2 USB DIO 16H User Manual Warranty Prior to shipment ACCES equipment is thoroughly inspected and tested to applicable specifications However should equipment failure occur ACCES assures its customers
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