What's New ========================================== Jun.26, 2018 v2.13.14 Add: Supports new model LRA-900-E. COM1= RS-232 (TX/RX/GND). ========================================== Mar.06, 2018 v2.13.12 Fix: Terminal program may show garbage on screen when using text mode. Add: Supports new model SG-GW-4. COM1= RS-485 (D+/D-) COM2= RS-485 (D+/D-) ========================================== Jan.24, 2018 v2.13.11 Fix: tDS-718-D CTR/RTS pins do not work correctly. ========================================== Dec.26, 2017 v2.13.10 Add: Supports new model JC-SG-4. COM1= RS-485 (D+/D-) COM2= RS-485 (D+/D-) ========================================== Nov.28, 2017 v2.13.09 Add: Supports new model iP-8441/8841. COM1= RS-232 (3-wire) COM2= RS-485 (D+/D-) COM3= RS-232 (5-wire) and RS-485 (D+/D1) COM4= RS-232 (9-wire) Add: Supports new model ET-8KP4/8KP8. COM1= RS-232 (TX/RX/GND) ========================================== Nov.17, 2017 v2.13.08 Fix: Wrong configuration command 38 is used for DSR/DTR mode setting on iDS-700 series. Use command 40 instead. Fix: Filter off some un-used CTS/DTR settings depending on supported pins. This reduces few Ethernet loadings when opending a port. ========================================== Sep.06, 2017 v2.13.07A Fix: The VxComm Utility shows wrong Windows 10 version. Driver version is still v2.13.07 (Aug.24, 2017). ========================================== Aug.24, 2017 v2.13.07 Fix: There is a potential issue that may block or crash the system when close virtual COM ports. ========================================== Jul.28, 2017 v2.13.06 Add: Supports tDS-2200 series modules. Chg: Rebuild Terminal/PDS_Diag utility programs with new IDE. ========================================== Apr.19, 2017 v2.13.05B Fix: Resign driver on Microsoft DevPortal for supporting Windows 10 build 1607. ========================================== Feb.21, 2017 v2.13.05A Fix: Repack the installation program to allow working on Windows Server 2016. ========================================== Apr.07, 2016 v2.13.05 Add: Add mscomm32.ocx and mswinsck.ocx componments for the built-in Modbus RTU/TCP master tools. Fix: Add protection check for preventing a potential crash issue. Chg: Use EV CodeSign and SHA256 to meet the requirement of the Windows 10. The SHA256 is not supported by old systems like Windows Vista/Server 2003/2008, so from now on the VxComm Driver/Utility does not support Vista too. Windows 7 requires SP1 to support SHA256. Automatic Windows Update is recommended for supporting SHA256. Deprecation of SHA-1 Hashing Algorithm for Microsoft Root Certificate Program https://technet.microsoft.com/en-us/library/security/2880823 Availability of SHA-2 Hashing Algorithm for Windows 7 and Windows Server 2008 R2 https://technet.microsoft.com/en-us/library/security/3033929 For manual updates, install the 3035131 update before installing the 3033929 update. ========================================== Sep.25, 2015 v2.13.04 (last version for Windows Vista/Server 2003/2008) Add: Supports iDS-448 model. ========================================== Jul.20, 2015 v2.13.03 Add: Supports GTP-500 model. ========================================== Jun.22, 2015 v2.13.02 Chg: Disable the XON/XOFF configuration check. Users have to take care by them-self that the XON/XOFF should not be the same. ========================================== May.12, 2015 v2.13.01 Add: Supports customized SL-PM515 model. ========================================== Mar.26, 2015 v2.13.00 Chg: Adjust the memory usage. Fix: Server name may not show in utility correctly when adding server. Fixed. Add: Support virtual COM ports up to COM512. Add: Support group configuration via UDP (Search-List window). Includes DHCP/IP/Mask/Gateway/Alias settings. Add: Support ping multiple devices(Search-List window). ========================================== Jan.07, 2015 v2.12.18 Fix: An memory leak issue when reconnect on Windows Server 2008. Fixed. Windows XP does not have this issue. Fix: Utility cannot configure port 9 of the PDS-5105D-MTCP. Fixed. Chg: Small change on the return code when closing COM port. ========================================== Dec.19, 2014 v2.12.16 Add: Add "Ignore Write Error" option in Driver Options page. This is usually used with the "Fast Open (Allow Always Open)" function, since we may want **NO** error reports when disconnected. Add: Add Driver Options menu item and provide a Fast Open (Allow Always Open) option. When the "Fast Open (Allow Always Open)" option is enabed, the driver creates the connection later instead of blocking the COM open operation for waiting the creation of the connection. This causes a fast response on open COM ports, but no error reported when open if there is connection problem. ========================================== Dec.13, 2014 v2.12.15 Fix: Fix a bug when failed creating connections. Add: Add nwe tools menu items Terminal / Modbus RTU Master / Modbus TCP Master. Fix: The remapping function of the utility does not work correctly. Fixed. Fix: The diag program may hang when working with very old firmware. Fixed. Chg: Records the last choice of the option "Re-assign COM number for all subsequent ports". ========================================== Nov.07, 2014 v2.12.11 Fix: A potential crash bug on driver for flow-control function is fixed. Chg: Hide BOOTP message/records of the utility. ========================================== Oct.09, 2014 v2.12.10 Add: Supports XON/XOFF and CTS/RTS flow-control for iDS-700 series. Fix: DSR signal status may wrongly reported by the driver. Fixed. ========================================== Jun.24, 2014 v2.12.09 Fix: The utility program may crash when restart driver. Fixed. Fix: The terminal program may crash when receiving large data. Fixed. Fix: The diagnostic program may terminate unexpected. Fixed. ========================================== May.20, 2014 v2.12.08 Add: Supports new model I-7550-E. ========================================== Apr.24, 2014 v2.12.07 (Win XP ~ Win 8) Add: Supports EnableWriteBuffer/AutoFlushTime parameters in the Import/Export functions of the VxComm Utility. Fix: The port1 of slot1 for PDS-800 is not remapped correctly in VxComm Utility. Fixed. Fix: Supports dual-LAN when searching modules. ========================================== ****************************************** ========================================== Jan.22, 2014 v2.12.06 (Last version that supports the Windows 2000) Fix: Fix a potential crash problem under Win7 Pro x64. ========================================== Dec.26, 2013 v2.12.05 Add: Supports iDS-700/100 new models. ========================================== Dec.11, 2013 v2.12.04 Fix: Fix a potential crash problem under Win7 Pro x64. ========================================== Oct.30, 2013 v2.12.03 Add: Supports iDS-7000/1000 new models. ========================================== May.24, 2013 v2.12.02 Add: Supports RMV-511/512 new model. RMV-511/512: COM1=RS-485. ========================================== Mar.22, 2013 v2.12.01 Add: Supports I-7547 and RMV-760-MTCP new models. I-7547: COM1=RS-232, COM2=RS-232 with fixed baudratre/data format. RMV-760-MTCP: COM1=RS-232, COM2=RS-485/422. ========================================== Mar.07, 2013 v2.12.00 Add: Supports Write-Buffer to collect small packets into big one. ========================================== Jan.29, 2013 v2.11.13 Add: Supports GRP-520/520P, RMV-531. GRP-520 (COM1=RS-485, COM2=3-wire RS-232) GRP-520P (COM1=RS-485, COM2=3-wire RS-232, COM3=3-wire RS-232) RMV-531 (COM1=3-wire RS-232, COM2=RS-485) ========================================== Dec.27, 2012 v2.11.12 Add: Supports ZT-2570/ZT-2571 model. COM1=Disabled. COM2=Virtual COM. ========================================== Jul.20, 2012 v2.11.10 Add: Add option in port configuration page allowing user to diable the purge command. Then the TX/RX buffer will not be cleared by PurgeComm. ========================================== Jul.12, 2012 v2.11.09 Change: Set the CTS/DSR status ON as default. ========================================== May.10, 2012 v2.11.08 Add: Supports M2M-520-AV model. ========================================== Feb.09, 2012 v2.11.07 Fix: The mask function does not work correctly, and causes some application busy on this. Fixed. ========================================== Jan.06, 2011 v2.11.06 Fix: The driver may have potential crash problem on few multi-core computer. Add some more synchronization to prevent problem. ========================================== Dec.20, 2011 v2.11.05 Change: The M2M-710D is now supporting 2 serial ports. ========================================== ****************************************** ========================================== May.12, 2011 v2.11.04 *** This is the last update for the Windows NT 4.0 driver. ******* Add: Supports new model GT-543, tDS-724 and tDS-734. Add: Add registry setting for selecting skip or return when serial port open errors. Double-click the IgnoreOpenErrors.reg file for skipping errors. Double-click the RejectOpenErrors.reg file for reject when errors (default). Note: Need to restart the driver after change the configuration. ========================================== Nov.18, 2010 v2.11.03 Add: Supports new model name PDS-5105D-MTCP. ========================================== Aug.30, 2010 v2.11.02 Fix: The terminal program of the VxComm Utility now supports sending 0x00 char for Modbus RTU command. ========================================== Aug.23, 2010 v2.11.01 Change: The driver allows users to set the baurate and data format on RS-485 port 2, while other settings on this port are not allowed. Now, we change to rule to enable more settings such as CTS/RTS, PurgeComm... etc. This would be usefult to clear the output/input buffer when there is something wrong. Ps. Other ports has no this limitation. ========================================== Aug.13, 2010 v2.11.00 Fix : Sometimes, there may have data shift problem when running the VxComm driver in a heavy loading and multi-core (or dual-core) computer. The potential problem is fixed in this version, and it is recommended to update the driver if you got above issue. ========================================== Jul.09, 2010 v2.10.01 Change: TDS-700 series is changed to tDS-700 series. Supports the tDS-700 series tiny device server. ========================================== Mar.24, 2010 v2.10.00 Add : Supports 64-bit Windows XP/2008/Vista/7. Tested OK with 64-bit Windows XP Professional x64 Edition Version 2003 SP2, and 64-bit Windows Vista. 64-bit Windows 2008. 64-bit Windows 7. ========================================== Jan.18, 2010 v2.09.13 Add : Supports ZB-257x series. Supports TDS-722/725/732/735 series. Supports M2M-710D/711D/712D series. Supports 7540 module. ========================================== Dec.18, 2009 v2.09.12 Add : Supports PDS-220FC/FCS/FT series. ========================================== Nov.26, 2009 v2.09.11 Fix : Fix the port setting function for TDS-700. Add data bits 5 and 6, add stop bit 2, add parity Mark and Space. TDS-700 supports data bit 5 ~7, stop bit 1 ~ 2, parity None ~ Space; while 7188E/PDS-700 series's port 1/2 supports data bit 7 and 8 only. Fix : Modify the PDS_Diag.exe diagnostic program to support TDS-700, PPDS-700-MTCP/IP67, M2M-7255 and M-4132 series. ========================================== Nov.10, 2009 v2.09.10 Add : Supports ET-87Pn series. It provides 1 serial port and 1 port I/O. It does not supports I-8K serial modules. ========================================== Oct.21, 2009 v2.09.09 Change: The M2M-7255 model is renamed to M2M-720-A. Modify the utility to support new model M2M-720-A. ========================================== Sep.14, 2009 v2.09.08 Add : Supports PPDS-700-IP67, PPDS-700-MTCP, TDS-700 new models. Supports PDS-745i, M-4132, M2M-7255 new models. Fix : Enable "Set IP/Mask/Gateway" button for all other PDS. The function may still failed if the firmware is too old to support the configuration method. Add : Supports resizing main window. ========================================== May.06, 2009 v2.09.07 Add : Supports CxC-540 new model. Not released version. ========================================== Feb.03, 2009 v2.09.06 Fix : Fix a driver bug when mapping virtual COM port to COM256. Max. devices and ports are 256. Fix : Fix a driver bug when processing unicode string, this may cause some system blue screen. Fixed in this version. Add : Add "Remove All Servers" feature on the menu item. ========================================== Nov.13, 2008 v2.09.05 Fix : The auto-reconnect function does not work correct for 1-port DS-700. This problem is fixed on this version. Fix : Terminal function may select wrong COM port name sometimes. Fix this small issue. ========================================== Oct.07, 2008 v2.09.04 Fix : Terminal function sometimes cannot send CR (0x0D) automatically. Fixed it in this version. Add : Supports PDS-775 new model (for PDS-775-A). ========================================== Sep.05, 2008 v2.09.03 Fix : Add-servers feature. Copy the start-IP to end-IP when start-ip is changed by user. This reduce typing errors. Support "Cancel" button when add multiple servers. Add : Add PDS diagnostic program. Get system information and VxComm driver status. Ping host IP address. Verify command port connection. Verify data ports connections. Save log to file. Supports PDS-700, DS-700, 7188EN, PDS-800, I8KE series. ========================================== Sep.01, 2008 v2.09.02 Add : Supporting PDS-800 series. Supporting iPAC8K series. Add : Supporting Redundant IP Address. Set 0.0.0.0 to disable the redundant IP feature. When the IP address is not available for connect, the driver will try next IP address. Fix : Terminal.exe utility program continue shows error message box when TCP connecting failed. Fixed. This program may select wrong com port in the UI. Fixed. For example, we selects COM3 in VxComm Utility but the Terminal.exe selects COM39 by default. Fix : VxComm Utility may show multiple Port I/O when the device name has more ports assigned that out the default number of ports. Fixed. Fix : UDPSearch.DLL supports module name length upto 15 bytes only. Change to 30 bytes for supporting PDS-800:n-mmmmmmmm modulized models. Fix : Fix COM1 mapping problem. Note, you have to disable both COM1 and COM2 on your PC BIOS. If you keep PC COM2 enabled, the system driver will also create COM1 oject. This cause VxComm Driver failed to create it's own Virtual COM1 on the system. ========================================== Jul.09, 2008 v2.09.01 Fix : Number of COM ports on a single PDS that large than 32 may cause driver crash. Fixed. Fix : When 7188EN sends out packet with wrong CRC checksum, this may cause VxComm Driver failed to get all data when the packet is resend. This also cause receiving operation is stopped untill restore the connection. Fixed. Change : Change the Keep-Alive thread to wakeup every 2 seconds and then check status of connections. This causes a better response time since it reopen the connection as soon as possible when it is broken. Add : Supports ET-6000 and ET2-6000 modules. ========================================== Apr.09, 2008 v2.09.00 Add : Creates driver service on system database without reboot computer after install the VxComm Driver. Add : Supports UDP Search feature. Test with PDS-782 and VCOMM firmware v3.2.30[11/30/2007]. Add : Add VxComm Utility into exception list of Windows XP firewall. This allows VxComm Utility can search 7188E/PDS devices without Windows firewall blocking. Add : Support Windows Vista32. Add manifest in the utility to require Administrator right for accessing registry. This is the Vista UAC limitation. Add : Supports multiple windows for COM or TCP/IP testing. Add : Supports 7186EX, 8441, 8841 devices. Supports DS-700 and PDS-700 series. Add : Add "Web Configuration" button. Add "Ping Server" for using system "Ping.exe" to ping the device. Add : Add "Batch Add Servers" feature for mass devices installation. Supports Timeout/Connection Broken Time/Keep-Alive Time settings on Advanced Options. Supports virtual COM ports mapping automatically. Remove "Add Server" feature on the main form. Uses the "Batch Add Servers" feature instead. Change : Change the max. number of servers to 255. The max. number of COM ports is still 256. Change : Configuration file is changed to XML format. Change : Enable user to set Fixed-config for all ports at a time. Enable user to set un-map for all ports at a time. Arrange the Server-options and Device-information in a single dialog. Arrange the Port-mapping and Port-configure in a single dialog. Fix : Fix a potential timing issue on a Dual-CPU (or multi-CPU) system. The old driver may stop the OS when disconnecting sockets. Fix : 7188E4's DCD/RI signals does not show correct status. Fixed. Remove : Remove SendTcp.exe from the installation. ========================================== Dec.20, 2005 v2.08.11 Fix : Some PC may not work when the devices up to 33 pcs. Fix it. Max. number of devices should be 100 pcs. Change : Change the default Keep-Alive time from 7 seconds to 120 seconds (2 minutes, about 1/3 of 7188E's default system timeout-- 300 seconds or 5 minutes). This reduces the communications, especially good in a large network environment. ========================================== Nov.15, 2005 v2.08.10 Fix : VxComm Utility may not work on Windows NT 4.0 when the server data is empty. Fix it! ========================================== Mar.09, 2005 v2.08.09 (Tested with I-8831 + I-8114 x 4 pcs + VC8_3301.exe Feb.24, 2005.) Change : Using a union structure to contains COM port number, FixedConfig , SlotIndex (0~8), PortIndex(1-16) informations. These new structure is useful for I-8000 to work with serial port modules such as I-8114...etc. Add : Add the ICP DAS Logo. ========================================== Dec.30, 2004 v2.08.07 Fix : When removing a server from the utility, the related virtual com ports does not shown in the available com port list. Fix it for UI operations conveniently. ========================================== Dec.28, 2004 v2.08.06 (Tested with I-8831 + I-8114 x 4 pcs + VC8_3223.exe Dec.28, 2004.) Fix : The DCD/RI/DTR/DSR/CTS/RTS signals are not correct when port number > 9. Fix it. Fix : Import/Export features does not work correctly for 8KEx, I8000E-xx and PDS8000-xx devices. Fix it. ========================================== Dec.24, 2004 v2.08.05 Add : Supports I8000E-xx, L8000E-xx and PDS8000-xx Device Servers with I-8114 multi-port serial modules. Add : Shows related information when re-starting the driver. ========================================== Aug.19, 2004 v2.08.03 Add : Supports 28800 bps baud rate. Add : Supports DSR/RI/DCD signal detecting. (Not H/W flow control) Supports DTR signal setting. These should works with the VxComm Server v3.2.01[07/20/2004] or newer one. Move: Remove the Help files from the VxComm installation package, and place the help files in CD and web site standalone. ========================================== Apr.27, 2004 v2.08.02 Add : Supports 8KE4 and 8KE8 devices. Change : Rename the "Port 7000" to "Port I/O". ========================================== Mar.30, 2004 v2.08.00 Add : Supports more menu items, such as "Remove Server", "Server Options", "Port Mapping" and "Port Configuration". Add : Adds a simple COM port test feature to send/receive data to/from a specified COM port. Add : Adds a simple TCP port test feature to send/receive data to/from a specified TCP port. ========================================== Sep.25, 2003 v2.07.01 Add : Add MENU to contain more features. "Import Configuration" : Import configuration from a file. "Export configuration" : Export configuration into a file. System Information : Shows ... OS version, System directory, numbers of CPU installed, CPU type. VxComm Driver version, file size, file time, driver status. Device Information : Show ... Server name, firmware version, MiniOS7 version, Max. sockets, System Timeout, share mode. Gateway, sub-net Mask, MAC address. The above information is useful for trouble-shooting. Change : Use menu item to replace the "Import / Export" button. (remove the button.) ========================================== Sep.19, 2003 v2.07.00 Add : Supports Dual-CPU computer. VxComm Driver has been tested OK under Windows NT 4.0, Windows 2000/XP and Windows Server 2003 with the Dual-CPU computer. Add : VxComm Utility supports Baud rate and Data format configuration via TCP connection. Add: Supports "Use 7188E/8000E current settings (Fixed Configuration)". By using this feature, the VxComm Driver won't change the Baudrate, data format and CTS/RTS control mode of the 7188E/8000E device. This improves the stability and less conflicts with each client. Add : Add "Timeout", "Port7000 port" and "Command TCP port" parameters when configuring the 7188E/8000E virtual COM ports. Fix : Get current baud rate settings before test "02" command. This prevents the different baud rate setting conflicts. ========================================== Mar.06, 2003 v2.06.12 Add : Add a "Connect-Timeout" parameter in the "Server Options", this can let user to adjust the connect-timeout value. The default timeout is 5000 ms. ========================================== Nov.08, 2002 v2.06.07 ( Tested with VCOM3009.exe 11/6/2002 firmware. ) Fix : The VxComm Driver failed to send a specified character when application calling TransmitCommChar() API. Fix it. Add : Supports 7188E7 device. (7188EX + X512) ========================================== Oct.22, 2002 v2.06.05 Fix : The CMD port (port 10000) is lost when the first client is closed. Fix it! Add : Add VxComCfg.DLL and VB5 sample program to support calling the Import function from users's program. User can dynamically imports a specified configuration from a file. For more information, please refer to the sample.cfg and the VxComCfg folder. ========================================== Sep.25, 2002 v2.06.04 Change : Removes default settings (1200bps, 8N1...) from VxComm Driver. Users have to make a correct setting before communications. This prevents a short time conflicts during the COM port setting by 2nd (or more) client. Change : The default value of ConnectionBroken is changed to 180,000ms. ( = 180 seconds = 3 minutes ) Change the parameter from 20 seconds to 180 seconds, this reduces the times of reconnecting. Change : VxComm Driver will reconnect the specified COM port, if there has no sendings/Receivings in the past ConnectionBroken time. (Last version just do it when connections are broken. ) ========================================== Sep.11, 2002 v2.06.03 (Tested with VCOM3009.exe 2002/09/05 firmware.) Improve : Improves the auto-reconnect mechanism to let it works better. ========================================== Aug.20, 2002 v2.06.01 Add : VxComm Utility supports "Import" and "Export" features. It is used to export the current settings into a configuration file, and to import settings from a configuration file. For more information, please refer to the "sample.cfg" file. ========================================== Aug.05, 2002 v2.06.00 Add : Suuports CTS/RTS flow control. (7188E firmware must be VCOM3007.exe 2002/07/26 or newer.) +------------------------+-------------------------------+ | Win32 | 7188E | +------------------------+-------------------------------+ | RTS_CONTROL_DISABLE | Mode 1, Default RTS low | | RTS_CONTROL_ENABLE | Mode 1, Default RTS high | | RTS_CONTROL_HANDSHAKE | Mode 3, Library auto-control | | RTS_CONTROL_TOGGLE | N/A | +------------------------+-------------------------------+ When writting, if CTS_CONTROL_HANDSHAKE is set, the driver will wait until the CTS line is high or timeout occurred. ( It's about 9 seconds for waiting CTS line to high. ) ========================================== May.21, 2002 v2.05.01 Fix : MSComm.OCX always waiting for I/O STATUS_SUCCESS even any error occursed. Fix driver to support it and support the EVENT_ERR. Fix : The connection status sometimes become invalid. Try to close and re-open it. ========================================== May.02, 2002 v2.05 Add : Supports 8430/8830 + 8142 * 4 (total 11 COM ports) Add : Supports Break-Signal sending from VxComm Driver(PC) to VxComm Server(7188E). The version of VxComm Server(7188E) should greater than (or equal) ver3.0.06. ========================================== Dec.25, 2001 v2.03 Change : VxComm Driver/VxComm Utility/SendTcp programs support the I-8430/I-8830 port 1, 3 and support the I-8431 /I-8831 port 1, 3, 4. ========================================== Dec.15, 2001 v2.02 Change : Dynamic creates the TCP connections when need, so it will be faster to open the first port. Change : Port list in the VxComm Utility enables the full row selection. Users can operating the VxComm Utility more easily. Change : Remove the IP-Address control from the VxComm Utility. This control is included in the IE 4.0 or later. If the computer system doesn't provide this control, it will cause the VxComm Utility fails. Remove this one to prevent the problems. ========================================== Dec.03, 2001 v2.01 Fix : Fix the driver to supports up to COM256, test OK!! ========================================== Nov.28, 2001 v2.00 Beta 7 Fix : Supports the EV_TXEMPTY events for WaitCommEvent(). Fix : VxComm Utility get the version number and check the 02 and 03 command when connecting to the 7188E server. VxComm Utility fails to filter the ComNoIO that is used by 8430. Fix it. ========================================== Nov.01, 2001 v2.00 Beta 4 Add : Supports Auto-Reconnection mechanism when the connection -broken. VxComm Utility supports the Keep-Alive-Time, ConnectionBroken settings. Fix : Installation package keeps the registry settings of the last VxComm driver settings. Fix : Use 02, 03 command to change the baudrate, data format without saving to EEPROM. (Last version use 06, 07 command to change and save.) This new version of VxComm Driver (PC) must works with newer version of VxComm Server (7188E). Change : Add 0x0D char to the end of command. Add : VxComm Utility, add the "Check Duplicate" and "Check Server" options. Check Duplicate : This option will check the IP address if duplicated with the exist servers. Check Server : This option will connect to the IP address and get the server's name. Fix : Changes the number of session (array) from 3 to 9, this supports up to 8 ports (7188E8). Fix : VxComm Utility checks for the used com ports. Change : Change the MAX_PORT to 256 COM ports, but the MAX_SERVER still setting to 100. Add : Supports 8430, 8431, 8830, 8831 main boards. ========================================== Aug.31, 2001 v1.04.01 Fix : Support EV_RXCHAR and EV_RXFLAG events for WaitCommEvent() Note : BSOD stands for "Blue Screen of Death" of MS Windows.