Future Technology Devices International Ltd USB TO RS485 UART SERIAL CONVERTER PCB Datasheet Document Reference No.: FT_000120 Version 1.2 Issue Date: 27-05-11 Future Technology Devices International Limited (FTDI) Unit1, 2 Seaward Place, Centurion Business Park,, Glasgow G41 1HH United Kingdom Tel.: +44 (0) 141 429 2777 Fax: + 44 (0) 141 429 2758 E-Mail (Support): [email protected] Web: http://www.ftdichip.com Copyright © 2008 Future Technology Devices International Limited Neither the whole nor any part of the information contained in, or the product described in this manual, may be adapted or reproduced in any material or electronic form without the prior written consent of the copyright holder. This product and its documentation are supplied on an as-is basis and no warranty as to their suitability for any particular purpose is either made or implied. Future Technology Devices International Ltd will not accept any claim for damages howsoever arising as a result of use or failure of this product. Your statutory rights are not affected. This product or any variant of it is not intended for use in any medical appliance, device or system in which the failure of the product might reasonably be expected to result in personal injury. This document provides preliminar y information that may be subject to change without notice. No freedom to use patents or other intellectual property rights is implied by the publication of this document. Future Technology Devices International Ltd, Unit1, 2 Seaward Place, Centurion Business Park, Glasgow, G41 1HH, United Kingdom. Scotland Registered Number: SC136640 Copyright © 2011 Future Technology Devices International Limited Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB 1 Description The USB-RS485-PCB is a USB to RS485 level serial UART converter PCB incorporating FTDI‟s FT232RQ USB to Serial UART interface IC device which handles all the USB signalling and protocols. The PCB provides a fast, simple way to connect devices with a RS485 interface to USB. Each USB-RS485-PCB contains a small internal electronic circuit board, utilising the FT232R plus a USB type-A connector. The FT232R datasheet, DS_FT232R, is available at http://www.ftdichip.com. The integrated electronics also include an RS485 transceiver plus Tx and Rx LEDs which give a visual indication of UART traffic. The PCB is USB powered and USB 2.0 full speed compatible. Each PCB supports a data transfer rate up to 3 Mbaud and supports the FTDIChip-ID™, with a unique USB serial number programmed into the FT232R. This feature can be used to create a security or password protected file transfer access using the PCB. Further information and examples on this feature are available at http://www.ftdichip.com under FTDIChip-ID Projects. The USB-RS485-PCB requires USB drivers, available free from http://www.ftdichip.com, which are used to make the FT232R on the PCB appear as a virtual COM port (VCP). This then allows the user to communicate with the USB interface via a standard PC serial emulation port (for example TTY). Another FTDI USB driver, the D2XX driver, can also be used with application software to directly access the FT232R on the PCB though a DLL. This is illustrated in the Figure 1.1. VCP TTY USB-RS485-PCB USB RS485 UART SIGNALS Virtual COM Port D2XX DLL TTY USB-RS485-PCB USB RS485 UART SIGNALS Software application access to USB via D2XX Figure 1.1 Using the USB-RS485-PCB Copyright © 2011 Future Technology Devices International Limited 1 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB 1.1 Part Number The following Table 1.1 gives details of the USB-RS485-PCB. Part Number Description USB-RS485-PCB USB to RS485 level UART PCB Table 1.1 USB-RS485-PCB Part Number Copyright © 2011 Future Technology Devices International Limited 2 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB Table of Contents 1 Description ..................................................................................... 1 1.1 2 Part Number.................................................................................................. 2 Typical Applications ........................................................................ 4 2.1 Driver Support .............................................................................................. 4 2.2 Features ........................................................................................................ 4 3 Features of FT232R applicable to USB-RS485-PCB ......................... 5 4 USB-RS485-PCB Connector Pin Out and Mechanical details ............ 6 4.1 USB-RS485-PCB Signal Descriptions ............................................................. 8 4.2 USB-RS485-PCB Electrical Parameters .......................................................... 9 4.3 Local Echo ................................................................................................... 10 5 USB-RS485-PCB Circuit Schematic ............................................... 11 6 Contact Information ..................................................................... 12 Appendix A – PCB EEPROM Configuration .......................................... 14 Appendix B – List of Figures and Tables ............................................. 15 Appendix C – Revision History ........................................................... 16 Copyright © 2011 Future Technology Devices International Limited 3 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB 2 Typical Applications USB to Serial RS485 Level Converter. USB Instrumentation PC interface. Upgrading Legacy Peripherals to USB. USB Industrial Control. Interface Microcontroller UART or I/O to USB. USB password protected file transfers. Interface FPGA / PLD to USB. 2.1 Driver Support Royalty free VIRTUAL COM PORT Royalty free D2XX Direct Drivers (VCP) DRIVERS for... (USB Drivers + DLL S/W Interface) Windows 98, 98SE, ME, 2000, Server 2003 and Server 2008 Windows 98, 98SE, ME, 2000, Server 2003 and Server 2008 Windows XP and XP 64-bit Windows XP and XP 64-bit Windows Vista and Vista 64-bit Windows Vista and Vista 64-bit Windows XP Embedded Windows XP Embedded Windows CE 4.2, 5.0 and 6.0 Windows CE 4.2, 5.0 and 6.0 Mac OS 8/9, OS-X Linux 2.4 and greater Linux 2.4 and greater Mac OS-X The drivers listed above are all available to download for free from www.ftdichip.com. Various 3rd Party Drivers are also available for various other operating systems – see www.ftdichip.com for details. 2.2 Features USB-RS485-PCB provides a USB to RS485 Serial UART interface. Support for FT232R FTDIChip-ID™ feature for improved security. Entire USB protocol handled by the electronics on the PCB. PCB is USB Powered – no external supply required. EIA/TIA-485 interface with low power requirements. X-On / X-Off software handshaking UART interface support for 7 or 8 data bits, 1 or 2 stop bits and odd / even / mark / space / no parity. Data transfer rates up from 300 baud to 3 Mbaud. Internal EEPROM with user writeable area. FTDI‟s royalty-free VCP allow for communication as a standard emulated COM port and D2XX „direct‟ drivers provide DLL application programming interface. Low USB bandwidth consumption. UHCI / OHCI / EHCI host controller compatible. USB 2.0 Full Speed compatible. -40°C to +85°C operating temperature range. RoHS compliant ESD Protection for RS-485 I/O‟s ±15kV Human Body Model (HBM) ±15kV EN61000-4-2 Air Gap Discharge ±8kV EN61000-4-2 Contact Discharge Copyright © 2011 Future Technology Devices International Limited 4 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB 3 Features of FT232R applicable to USB-RS485-PCB The USB-RS485-PCB uses FTDI‟s FT232RQ USB to serial IC device. This section summarises the key features of the FT232RQ which apply to the USB-RS485-PCB. For further details, and a full features and enhancements description consult the FT232R datasheet, this is available from www.ftdichip.com. Internal EEPROM. The internal EEPROM is used to store USB Vendor ID (VID), Product ID (PID), device serial number, product description string and various other USB configuration descriptors. Each USBRS485-PCB is supplied with the internal EEPROM pre-programmed as described in Appendix A – PCB EEPROM Configuration. The internal EEPROM descriptors can be programmed in circuit, over USB without any additional voltage requirement. It can be programmed using the FTDI utility called FT_Prog, which can be downloaded from the FTDI website (http://www.ftdichip.com/Support/Utilities.htm). Additionally, there is a user area of the internal EEPROM available to system designers to allow storing of data (note that this is not modified by FT_Prog). Lower Operating and Suspend Current. The FT232R has a low 15mA operating supply current and a very low USB suspend current of approximately 70μA. Low USB Bandwidth Consumption. The USB interface of the FT232R, and therefore the USB-RS485PCB has been designed to use as little as possible of the total USB bandwidth available from the USB host controller. FTDIChip-ID™. The FT232R includes the new FTDIChip-ID™ security dongle feature. This FTDIChip-ID™ feature allows a unique number to be burnt into each FT_232RQ during manufacture. This number cannot be reprogrammed. This number is only readable over USB can be used to form the basis of a security dongle which can be used to protect any customer application software being copied. This allows the possibility of using the USB-RS485-PCB as a dongle for software licensing. Further to this, a renewable license scheme can be implemented based on the FTDIChip-ID™ number when encrypted with other information. This encrypted number can be stored in the user area of the FT232R internal EEPROM, and can be decrypted, then compared with the protected FTDIChip-ID™ to verify that a license is valid. Web based applications can be used to maintain product licensing this way. An application note, AN232R-02, available from FTDI website (www.ftdichip.com) describes this feature. Extended Operating Temperature Range – The USB-RS485-PCB is capable of operating over an extended temperature range of -40º to +85ºC thus allowing it to be used in automotive or industrial applications. Copyright © 2011 Future Technology Devices International Limited 5 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB 4 USB-RS485-PCB Connector Pin Out and Mechanical details Resistor Termination 1 Resistor Termination 2 RED LED TOP GRN LED RS 485 Transceiver 5V BOTTOM Data- FT232R Data+ GND USB-RS485-PCB Rev 1 5V RED LED TOP GRN LED GND RS 485 Transceiver Data Data + BOTTOM FT232R 120Ω Resistor Termination 1 120Ω Resistor Termination 2 GND 5V USB-RS485-PCB Rev 2 Figure 4.1 USB-RS485-PCB Pin Out (Top is TOP View, Bottom is BOTTOM View) The mechanical details of the PCB are shown in the following diagram Figure 4.2 Additional pads were added to the PCB to allow for easier wiring which resulted in a Rev 2 PCB. There were no other changes between Rev 1 and Rev 2. Copyright © 2011 Future Technology Devices International Limited 6 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB 24.9 +/- 0.4 11.85 +/- 0.35 1.6 11.85 +/- 0.35 40.1 +/- 0.2 4.9 +/- 0.1 4.5 +/- 0.01 18.8 +/- 0.2 Dimensions in mm Figure 4.2 USB-RS485-PCB, Mechanical Details Copyright © 2011 Future Technology Devices International Limited 7 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB 4.1 USB-RS485-PCB Signal Descriptions Name Type Description GND GND Device ground supply pin. Pin 1 of 120R Terminating Resistor. Only Required if Terminator 1 Input the USB-RS485-PCB is the first or last device in a multi-drop RS485 System, to meet RS485 Termination Requirements. Power output. Default output is +5V when active, POWER Output 0V during suspend. If required, contact FTDI Sales Team ([email protected]). Switchable power to external device, 250mA max. OFF during suspend Data + Bi-Direction Data + Signal Data – Bi-Direction Data – Signal Pin 2 of 120R Terminating Resistor. Only Required if Terminator 2 Input the USB-RS485-PCB is the first or last device in a multi-drop RS485 System, to meet RS485 Termination Requirements. Table 4.1 USB-RS485-PCB Signal Descriptions Note: In some cases when termination is enabled, unexpected zero bytes can be received at the beginning or end of a message. To resolve this, biasing resistors can be added to the Data + and Data – lines to ensure that the lines go to an idle state when no node is driving data onto the bus. Typical values for these resistors would be: 750 ohms between Data + and +5V (POWER) 750 ohms between Data - and ground (GND) The resistors would be fitted externally to the USB-RS485-PCB as the board does not have footprints for them. Only one set of biasing resistors should only be used on the bus. They should not be added to the USBRS485-PCB node if another node on the bus is already providing biasing. Copyright © 2011 Future Technology Devices International Limited 8 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB 4.2 USB-RS485-PCB Electrical Parameters Parameter Description Minimum Typical Maximum Units Conditions The range is dependent on VCC_5V Output Power Voltage 4.25 5.0 5.25 V the USB port that the USBRS485-PCB is connected to. IO T Output Power Current Operating Temperature Range - 250 -40 +85 mA Must be less than 2.5mA during suspend. o C Table 4.2 USB-RS485-PCB Parameter Description Minimum Typical Maximum Units +12 V Conditions Receiver Input VCM Common-mode input voltage range -7 1.0 IN Input Current VIN = +12V mA –0.8 VTH VIHYST RIN Differential Threshold Voltage,VTH -0.2 Input Hysteresis Input Resistance, RIN 12 +0.2 VIN = –7V V 20 mV 15 kΩ Transmitter Output VOD Differential Output Voltage, dVOD 1.5 5 V With RL = 54Ω. CL = 50pF * Table 4.4 USB-RS485-PCB I/O Pin Characteristics * - The 54 ohms is the equivalent of two 120 ohm termination resistors placed on each side of the transmission line and the input impedance of 32 receivers on the line. Note: The VCC_5V output is switched by a transistor on the USB-RS485-PCB. This transistor will enable the VCC_5V output when the device is enumerated (it will disable the VCC_5V output when in USB suspend mode). Copyright © 2011 Future Technology Devices International Limited 9 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB Description Conditions Minimum Typical ESD HBM RS-485 Inputs and Outputs ±15 kV EN61000-4-2ContactDischarge RS-485 Inputs and Outputs ±8 kV EN61000-4-2AirGapDischarge RS-485 Inputs and Outputs ±15 kV Maximum Table 4.3 USB-RS485-WE ESD Tolerance 4.3 Local Echo RS485 systems often have local echo enabled. This means any data transmitted by a device is echoed back to itself. The USB-RS485-PCB allows for local echo to be enabled/disabled by changing a bit in the FT232R EEPROM. If CBUS4 in the EEPROM is set for “PWRON#”, local echo is enabled. If CBUS4 in the EEPROM is set for “TXDEN”, local echo is disabled. Users can enable/disable the local echo setting with the Echo Configuration Utility from http://www.ftdichip.com/Support/Utilities/USB-485%20Echo%20Configuration%20Utility.zip If required, other EEPROM settings (including local echo) can also be configured with the FT_Prog utility from http://www.ftdichip.com/Support/Utilities.htm The default for the local echo is disabled (CBUS4 set for “TXDEN”). Copyright © 2011 Future Technology Devices International Limited 10 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB 5 USB-RS485-PCB Circuit Schematic The circuit schematic of the USB-RS485-PCB, utilising the FTDI FT232R, is shown in Figure 5.1 Figure 5.1 Circuit Schematic of USB-RS485-PCB. Copyright © 2011 Future Technology Devices International Limited 11 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB 6 Contact Information Head Office – Glasgow, UK Future Technology Devices International Limited Unit 1, 2 Seaward Place, Centurion Business Park Glasgow G41 1HH United Kingdom Tel: +44 (0) 141 429 2777 Fax: +44 (0) 141 429 2758 E-mail (Sales) [email protected] E-mail (Support) [email protected] E-mail (General Enquiries) [email protected] Web Site URL http://www.ftdichip.com Web Shop URL http://www.ftdichip.com Branch Office – Shanghai, China Future Technology Devices International Limited (China) Room 408, 317 Xianxia Road, ChangNing District, ShangHai, China Tel: +86 (21) 62351596 Fax: +86(21) 62351595 E-Mail (Sales): [email protected] E-Mail (Support): [email protected] E-Mail (General Enquiries): [email protected] Web Site URL: http://www.ftdichip.com Branch Office – Taipei, Taiwan Future Technology Devices International Limited (Taiwan) 2F, No. 516, Sec. 1, NeiHu Road Taipei 114 Taiwan , R.O.C. Tel: +886 (0) 2 8797 1330 Fax: +886 (0) 2 8751 9737 E-mail (Sales) [email protected] E-mail (Support) [email protected] E-mail (General Enquiries) [email protected] Web Site URL http://www.ftdichip.com Branch Office – Hillsboro, Oregon, USA Future Technology Devices International Limited (USA) 7235 NW Evergreen Parkway, Suite 600 Hillsboro, OR 97123-5803 USA Tel: +1 (503) 547 0988 Fax: +1 (503) 547 0987 E-Mail (Sales) [email protected] E-Mail (Support) [email protected] Web Site URL http://www.ftdichip.com Copyright © 2011 Future Technology Devices International Limited 12 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB Distributor and Sales Representatives Please visit the Sales Network page of the FTDI Web site for the contact details of our distributor(s) and sales representative(s) in your country. Copyright © 2011 Future Technology Devices International Limited 13 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB Appendix A – PCB EEPROM Configuration Each USB-RS485-PCB is controlled by the FTDI FT232R IC. This FT232R device contains an EEPROM which contains the USB configuration descriptors for that device. When the PCB is plugged into a PC or a USB reset is performed, the PC will read these descriptors. The default values stored into the internal EEPROM are defined in Table 0.1 Default Internal EEPROM Configuration Parameter Value USB Vendor ID (VID) 0403h FTDI default VID (hex) USB Product UD (PID) 6001h FTDI default PID (hex) Serial Number Enabled? Serial Number Pull down I/O Pins in USB Suspend Yes See Note A unique serial number is generated and programmed into the EEPROM during device final test. Disabled Enabling this option will make the device pull down on the UART interface lines when the power is shut off (PWREN# is high). Manufacturer Name FTDI Product Description See note Max Bus Power Current Power Source Device Type USB Version Notes USB-RS485-PCB 90mA Bus Powered FT232R 0200 Returns USB 2.0 device description to the host. Note: The device is be a USB 2.0 Full Speed device (12Mb/s) as opposed to a USB 2.0 High Speed device (480Mb/s). Remote Wake Up Disabled High Current I/Os Enabled Load VCP Driver Enabled Invert TXD Disabled Signal on this pin becomes TXD# if enable. Invert RXD Disabled Signal on this pin becomes RXD# if enable. Invert RTS# Disabled Signal on this pin becomes RTS if enable. Invert CTS# Disabled Signal on this pin becomes CTS if enable. Enables the high drive level on the UART and CBUS I/O pins. Makes the device load the VCP driver interface for the device. Table 0.1 Default Internal EEPROM Configuration The internal EEPROM on the PCB can be re-programmed over USB using the utility program FT_Prog, which can be downloaded from http://www.ftdichip.com/Support/Utilities.htm. Users who do not have their own USB Vendor ID but who would like to use a unique Product ID in their design can apply to FTDI for a free block of unique PIDs. Contact FTDI support for this service. Copyright © 2011 Future Technology Devices International Limited 14 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB Appendix B – List of Figures and Tables List of Figures Figure 1.1 Using the USB-RS485-PCB........................................................................................................... 1 Figure 4.1 USB-RS485-PCB Pin Out (Top is TOP View, Bottom is BOTTOM View) .................................. 6 Figure 4.2 USB-RS485-PCB, Mechanical Details .......................................................................................... 7 Figure 5.1 Circuit Schematic of USB-RS485-PCB. ..................................................................................... 11 List of Tables Table 4.1 USB-RS485-PCB Signal Descriptions ........................................................................................... 8 Table 4.2 USB-RS485-PCB .............................................................................................................................. 9 Table 4.3 USB-RS485-WE ESD Tolerance ................................................................................................... 10 Table 0.1 Default Internal EEPROM Configuration ..................................................................................... 14 Copyright © 2011 Future Technology Devices International Limited 15 Document Reference No.: FT_000120 Datasheet Version 1.2 Clearance No. FTDI#80 USB to RS485 UART Serial Converter PCB Appendix C – Revision History Version Draft First Draft January, 2009 Version 1.0 First Release 21st January, 2009 Version 1.01 Corrected the PCB diagram and TW address 09th February, 2009 Version 1.02 Added Rev 1 and Rev 2 mechanical diagrams 10th March, 2009 Version 1.1 Edited Figure 4.1 and table 4.1, signals A Data+ and B DataAdded section 1.2 USB compliant Logo 29th July 2010 Version 1.2 Removed section 1.2 All diagram/schematic pins now labelled as „Data +‟ and „Data Added links to FT_Prog utility which replaces MPROG Added link to echo configuration utility Updated table 4.2 as 5V output is available on standard PCB Added details of external biasing resistors 27th May 2011 Copyright © 2011 Future Technology Devices International Limited 16