%all.entities; ]> $Date: 2023-04-21 21:59:02 +0000 (Fri, 21 Apr 2023) $ VBoxManage-controlvm 1 VBoxManage-controlvm change state and settings for a running virtual machine &product-name; VBoxManage controlvm uuid vmname pause VBoxManage controlvm uuid vmname resume VBoxManage controlvm uuid vmname reset VBoxManage controlvm uuid vmname poweroff VBoxManage controlvm uuid vmname savestate VBoxManage controlvm uuid vmname acpipowerbutton VBoxManage controlvm uuid vmname acpisleepbutton VBoxManage controlvm uuid vmname reboot VBoxManage controlvm uuid vmname shutdown --force VBoxManage controlvm uuid vmname keyboardputscancode hex hex VBoxManage controlvm uuid vmname keyboardputstring string string VBoxManage controlvm uuid vmname keyboardputfile filename VBoxManage controlvm uuid vmname setlinkstateN on off VBoxManage controlvm uuid vmname nicN null nat bridged intnet hostonly generic natnetwork device-name VBoxManage controlvm uuid vmname nictraceN on off VBoxManage controlvm uuid vmname nictracefileN filename VBoxManage controlvm uuid vmname nicpropertyN prop-name=prop-value VBoxManage controlvm uuid vmname nicpromiscN deny allow-vms allow-all VBoxManage controlvm uuid vmname natpfN rulename,tcpudp,host-IP,hostport,guest-IP,guestport VBoxManage controlvm uuid vmname natpfN delete rulename VBoxManage controlvm uuid vmname guestmemoryballoon balloon-size VBoxManage controlvm uuid vmname usbattach uuid address --capturefile=filename VBoxManage controlvm uuid vmname usbdetach uuid address VBoxManage controlvm uuid vmname audioin on off VBoxManage controlvm uuid vmname audioout on off VBoxManage controlvm uuid vmname clipboard mode disabled hosttoguest guesttohost bidirectional VBoxManage controlvm uuid vmname clipboard filetransfers on off VBoxManage controlvm uuid vmname draganddrop disabled hosttoguest guesttohost bidirectional VBoxManage controlvm uuid vmname vrde on off VBoxManage controlvm uuid vmname vrdeport port VBoxManage controlvm uuid vmname vrdeproperty prop-name=prop-value VBoxManage controlvm uuid vmname vrdevideochannelquality percentage VBoxManage controlvm uuid vmname setvideomodehint xres yres bpp display yes no x-origin y-origin VBoxManage controlvm uuid vmname setscreenlayout display on primary x-origin y-origin x-resolution y-resolution bpp off VBoxManage controlvm uuid vmname screenshotpng filename display VBoxManage controlvm uuid vmname recording on off VBoxManage controlvm uuid vmname recording screens all none screen-ID,screen-ID VBoxManage controlvm uuid vmname recording filename filename VBoxManage controlvm uuid vmname recording videores widthxheight VBoxManage controlvm uuid vmname recording videorate rate VBoxManage controlvm uuid vmname recording videofps fps VBoxManage controlvm uuid vmname recording maxtime sec VBoxManage controlvm uuid vmname recording maxfilesize MB VBoxManage controlvm uuid vmname setcredentials username --passwordfile= filename password domain-name --allowlocallogon= yes no VBoxManage controlvm uuid vmname teleport --host=host-name --port=port-name --maxdowntime=msec --passwordfile=filename --password=password VBoxManage controlvm uuid vmname plugcpu ID VBoxManage controlvm uuid vmname unplugcpu ID VBoxManage controlvm uuid vmname cpuexecutioncap num VBoxManage controlvm uuid vmname vm-process-priority default flat low normal high VBoxManage controlvm uuid vmname webcam attach pathname settings VBoxManage controlvm uuid vmname webcam detach pathname VBoxManage controlvm uuid vmname webcam list VBoxManage controlvm uuid vmname addencpassword ID password-file - --removeonsuspend= yes no VBoxManage controlvm uuid vmname removeencpassword ID VBoxManage controlvm uuid vmname removeallencpasswords VBoxManage controlvm uuid vmname changeuartmodeN disconnected server pipe-name client pipe-name tcpserver port tcpclient hostname:port file filename device-name VBoxManage controlvm uuid vmname autostart-enabledN on off VBoxManage controlvm uuid vmname autostart-delay seconds The VBoxManage controlvm command enables you to change the state of a running virtual machine (VM). The following sections describe the subcommands that you can use: The VBoxManage controlvm vmname pause command temporarily stops the execution of a VM. When paused, the VM's state is not permanently changed. The VM window appears as gray and the title bar of the window indicates that the VM is currently Paused. This action is equivalent to selecting Pause from the Machine menu of the GUI. The VBoxManage controlvm vmname resume command restarts the execution of a paused VM. This action is equivalent to selecting Resume from the Machine menu of the GUI. The VBoxManage controlvm vmname reset command performs a cold reset the VM. This command has the same effect on a VM as pressing the Reset button on a physical computer. The cold reboot immediately restarts and reboots the guest operating system (OS). The state of the VM is not saved prior to the reset, so data might be lost. This action is equivalent to selecting Reset from the Machine menu of the GUI. The VBoxManage controlvm vmname poweroff command powers off the VM. This command has the same effect on a VM as pulling the power cable on a physical computer. The state of the VM is not saved prior to poweroff, so data might be lost. This action is equivalent to selecting Close from the Machine menu of the GUI or to clicking the VM window's Close button, and then selecting Power Off the Machine. When in the powered off state, you can restart the VM. See . The VBoxManage controlvm vmname savestate command saves the current state of the VM to disk and then stops the VM. This action is equivalent to selecting Close from the Machine menu of the GUI or to clicking the VM window's Close button, and then selecting Save the Machine State. When in the saved state, you can restart the VM. It will continue exactly in the state you saved. The VBoxManage controlvm vmname acpipowerbutton command sends an ACPI shutdown signal to the VM. This command has the same effect on a VM as pressing the Power button on a physical computer. So long as the VM runs a guest OS that provides appropriately configured ACPI support, this command triggers an operating system shutdown from within the VM. The VBoxManage controlvm vmname acpisleepbutton command sends an ACPI sleep signal to the VM. So long as the VM runs a guest OS that provides appropriately configured ACPI support, this command triggers a sleep mechanism from within the VM. The VBoxManage controlvm vmname reboot command asks the guest OS to reboot itself. This commands requires Guest Additions to be installed in the VM. The VBoxManage controlvm vmname shutdown command asks the guest OS to halt + shutdown, optionally forcing the shutdown. This commands requires Guest Additions to be installed in the VM. The VBoxManage controlvm vmname keyboardputscancode command sends keyboard scancode commands to the VM. For information about keyboard scancodes, see . The VBoxManage controlvm vmname keyboardputstring command sends keyboard strings to the VM. The VBoxManage controlvm vmname keyboardputfile command sends a file to the VM. VBoxManage controlvm vmname setlinkstateN command enables you to connect or disconnect the virtual network cable from the network interface instance (N). Valid values are on and off. The default value is on. The VBoxManage controlvm vmname nicN command specifies the type of networking to use on the specified VM's virtual network card. N numbering begins with 1. The following valid network types are also described in : null specifies that the VM is is not connected to the host system. nat specifies that the VM uses network address translation (NAT). bridged specifies that the VM uses bridged networking. intnet specifies that the VM communicates with other VMs by using internal networking. hostonly specifies that the VM uses host-only networking. natnetwork specifies that the VM uses NAT networking. generic specifies that the VM has access to rarely used submodes The VBoxManage controlvm vmname nictraceN command enables you to trace the network traffic on the specified virtual network card (N). N numbering begins with 1. Valid values are on and off. The default value is off. If you did not configure a file name for the trace file then a default one is used, placing it in the VM subdirectory. The VBoxManage controlvm vmname nictracefileN command enables you to specify the name of the network traffic trace log file for the specified virtual network card (N). N numbering begins with 1. The VBoxManage controlvm vmname nicpromiscN command enables you to specify how to handle promiscuous mode for a bridged network. The default value of deny hides any traffic that is not intended for this VM. The allow-vms value hides all host traffic from this VM but enables the VM to see traffic to and from other VMs. The allow-all value removes this restriction completely. The VBoxManage controlvm vmname nicpropertyN prop-name=prop-value command, in combination with nicgenericdrv, enables you to pass property values to rarely-used network backends. Those properties are backend engine-specific, and are different between UDP Tunnel and the VDE backend drivers. See . The VBoxManage controlvm vmname natpfN command specifies a NAT port-forwarding rule. See . The VBoxManage controlvm vmname natpfN delete command deletes the specified NAT port-forwarding rule. See . The VBoxManage controlvm vmname guestmemoryballoon command changes the size of the guest memory balloon. The guest memory balloon is the memory allocated by the &product-name; Guest Additions from the guest OS and returned to the hypervisor for reuse by other VMs. The value you specify is in megabytes. See . The VBoxManage controlvm vmname usbattach command dynamically attaches a host USB device to the VM, which makes it visible. You do not need to create a filter. Specify a USB device by its Universally Unique Identifier (UUID) or by its address on the host system. Use the VBoxManage list usbhost command to obtain information about USB devices on the host system. Use the --capturefile option to specify the absolute path of a file in which to write logging data. The VBoxManage controlvm vmname usbdetach command dynamically detaches a host USB device from the VM, which makes it invisible. You do not need to create a filter. Specify a USB device by its UUID or by its address on the host system. Use the VBoxManage list usbhost command to obtain information about USB devices on the host system. The VBoxManage controlvm vmname audioin command specifies whether to enable or disable audio capture from the host system. Valid values are on, which enables audio capture and off, which disables audio capture. The default value is off. The VBoxManage controlvm vmname audioout command specifies whether to enable or disable audio playback from the guest VM. Valid values are on, which enables audio playback and off, which disables audio playback. The default value is off. The VBoxManage controlvm vmname clipboard mode command specifies how to share the guest or host OS's clipboard with the host system or VM. Valid values are disabled, hosttoguest, guesttohost, and bidirectional. The default value is disabled. See . This feature requires that the &product-name; Guest Additions are installed in the VM. The VBoxManage controlvm vmname clipboard filetransfers command specifies if it is possible to transfer files through the clipboard between the host and VM, in the direction which is allowed. Valid values are off and on. The default value is off. This feature requires that the &product-name; Guest Additions are installed in the VM. The VBoxManage controlvm vmname draganddrop command specifies the current drag and drop mode to use between the host system and the VM. Valid values are disabled, hosttoguest, guesttohost, and bidirectional. The default value is disabled. See . This feature requires that the &product-name; Guest Additions are installed in the VM. The VBoxManage controlvm vmname vrde command enables or disables the VirtualBox Remote Desktop Extension (VRDE) server, if installed. Valid values are on and off. The default value is off. The VBoxManage controlvm vmname vrdeport command specifies the port or range of ports to which the VRDE server can bind. The default value is default or 0, which is the standard RDP port, 3389. Also see the --vrde-port option description in . The VBoxManage controlvm vmname vrdeproperty command specifies the port numbers and IP address on the VM to which the VRDE server can bind. TCP/Ports specifies a port or a range of ports to which the VRDE server can bind. The default value is default or 0, which is the standard RDP port, 3389. Also see the --vrde-port option description in . TCP/Address specifies the IP address of the host network interface to which the VRDE server binds. When specified, the server accepts to connect only on the specified host network interface. Also see the --vrde-address option description in . VideoChannel/Enabled specifies whether to enable the VirtualBox Remote Desktop Protocol (VRDP) video channel. Valid values are 1 to enable the video channel and 0 to disable the video channel. The default value is off. See . VideoChannel/Quality specifies the JPEG compression level on the VRDE server video channel. Valid values are between 10% and 100%, inclusive. Lower values mean lower quality but higher compression. The default value is 100. See . VideoChannel/DownscaleProtection specifies whether to enable the video channel downscale protection feature. Specify 1 to enable the feature. This feature is disabled by default. When enabled, if the video's size equals the shadow buffer size, the video is shown in full-screen mode. If the video's size is between full-screen mode and the downscale threshold, the video is not shown as it might be an application window that is unreadable when downscaled. When disabled, the downscale protection feature always attempts to show videos. Client/DisableDisplay specifies whether to disable the VRDE server display feature. Valid values are 1 to disable the feature and an empty string ("") to enable the feature. The default value is an empty string. See . Client/DisableInput specifies whether to disable the VRDE server input feature. Valid values are 1 to disable the feature and an empty string ("") to enable the feature. The default value is 1. See . Client/DisableAudio specifies whether to disable the VRDE server audio feature. Valid values are 1 to disable the feature and an empty string ("") to enable the feature. The default value is 1. See . Client/DisableUSB specifies whether to disable the VRDE server USB feature. Valid values are 1 to disable the feature and an empty string ("") to enable the feature. The default value is 1. See . Client/DisableClipboard specifies whether to disable the VRDE clipboard feature. Valid values are 1 to disable the feature and an empty string ("") to enable the feature. To reenable the feature, use Client/DisableClipboard=. The default value is 1. See . Client/DisableUpstreamAudio specifies whether to disable the VRDE upstream audio feature. Valid values are 1 to disable the feature and an empty string ("") to enable the feature. To reenable the feature, use Client/DisableUpstreamAudio=. The default value is 1. See . Client/DisableRDPDR specifies whether to disable the RDP Device Redirection For Smart Cards feature on the VRDE server. Valid values are 1 to disable the feature and an empty string ("") to enable the feature. The default value is 1. See . H3DRedirect/Enabled specifies whether to enable the VRDE server 3D redirection feature. Valid values are 1 to enable the feature and an empty string ("") to disable the feature. See . Security/Method specifies the security method to use for a connection. See . Negotiate accepts both enhanced (TLS) and standard RDP security connections. The security method is negotiated with the client. This is the default value. RDP accepts only standard RDP security connections. TLS accepts only enhanced RDP security connections. The client must support TLS. Security/ServerCertificate specifies the absolute path of the server certificate to use for a connection. See . Security/ServerPrivateKey specifies the absolute path of the server private key. See . Security/CACertificate specifies the absolute path of the CA self-signed certificate. See . Audio/RateCorrectionMode specifies the rate correction mode to use. VRDP_AUDIO_MODE_VOID indicates that no mode is specified. Use this value to unset any audio mode that is already set. VRDP_AUDIO_MODE_RC specifies to use the rate correction mode. VRDP_AUDIO_MODE_LPF specifies to use the low pass filter mode. VRDP_AUDIO_MODE_CS specifies to use the client sync mode to prevent underflow or overflow of the client queue. Audio/LogPath specifies the absolute path of the audio log file. The VBoxManage controlvm vmname vrdevideochannelquality command sets the image quality, as a JPEG compression level value, for video redirection. Valid values are between 10% and 100%, inclusive. Lower values mean lower quality but higher compression. See . The VBoxManage controlvm vmname setvideomodehint command specifies the video mode for the guest VM to use. You must have the &product-name; Guest Additions installed. Note that this feature does not work for all guest systems. The VBoxManage controlvm vmname setscreenlayout command can be used to configure multiscreen displays. The specified screen on the guest VM can be enabled or disabled, or a custom screen layout can be configured. The VBoxManage controlvm vmname screenshotpng command takes a screenshot of the guest display and saves it as PNG in the specified file. filename specifies the name of the PNG file to create. display specifies the display number for the screen shot. For a single monitor guest display, this is 0. The VBoxManage controlvm vmname recording command enables or disables the recording of a VM session into a WebM/VP8 file. Valid values are on, which begins recording when the VM session starts and off, which disables recording. The default value is off. The VBoxManage controlvm vmname recording screens command enables you to specify which VM screens to record. The recording for each screen that you specify is saved to its own file in the machine folder. You cannot modify this setting while recording is enabled. all specifies that you record all VM screens. none specifies that you do not record any VM screens. screen-ID specifies one or more VM screens to record. The VBoxManage controlvm vmname recording filename command specifies the file in which to save the recording. You cannot modify this setting while recording is enabled. The default setting is to store a recording in the machine folder, using the VM name as the file name, with a webm file name extension. VBoxManage controlvm vmname recording videores command specifies the resolution of the recorded video in pixels. You cannot modify this setting while recording is enabled. Use the Settings tool to view the video recording settings, which are based on the resolution (frame size). See the Frame Size field on the Recording tab of the Display page to view the default value. Specify the resolution as widthxheight: width specifies the width in pixels. height specifies the height in pixels. The VBoxManage controlvm vmname recording videorate command specifies the bit rate, bit-rate, of the video in kilobits per second. Increasing this value improves the appearance of the video at the cost of an increased file size. You cannot modify this setting while recording is enabled. Use the Settings tool to view the video recording settings, which are based on the frame size. See the Video Quality field on the Recording tab of the Display page to view the default value. The VBoxManage controlvm vmname recording videofps command specifies the maximum frequency of the video to record. Video frequency is measured in frames per second (FPS). The recording skips any frames that have a frequency higher than the specified maximum. Increasing the frequency reduces the number of skipped frames and increases the file size. You cannot modify this setting while recording is enabled. Use the Settings tool to view the video recording settings, which are based on the frame size. See the Frame Rate field on the Recording tab of the Display page to view the default value. The VBoxManage controlvm vmname recording maxtime command specifies the maximum amount time to record in seconds. The recording stops after the specified number of seconds elapses. If this value is zero, the recording continues until you stop the recording. The VBoxManage controlvm vmname recording maxfilesize command specifies the maximum size of the recorded video file in megabytes. The recording stops when the file reaches the specified size. If this value is zero, the recording continues until you stop the recording. You cannot modify this setting while recording is enabled. The setcredentials command enables you to specify the credentials for remotely logging in to Windows VMs. See . username specifies the user name with which to log in to the Windows VM. --passwordfile=filename specifies the file from which to obtain the password for username. The --passwordfile is mutually exclusive with the --password option. --password=password specifies the password for username. This design does not conform to Oracle's security guidelines. You should not be able to specify a password on the command line because the password can be seen in a process listing. The --password is mutually exclusive with the --passwordfile option. --allowlocallogin specifies whether to enable or disable local logins. Valid values are on to enable local logins and off to disable local logins. The VBoxManage controlvm vmname teleport command initiates a teleporting operation between the specified VM and the specified host system. See . If you specify a password, it must match the password you specified when you issued the VBoxManage modifyvm command for the target machine. --host=hostname Specifies the name of the VM. --port=port Specifies the port on the VM that should listen for a teleporting request from other VMs. The port number can be any free TCP/IP port number, such as 6000. --maxdowntime=msec Specifies the maximum downtime, in milliseconds, for the teleporting target VM. --password=password Specifies the password that the source machine uses for the teleporting request. The request succeeds only if the source machine specifies the same password. This design does not conform to Oracle's security guidelines. You should not be able to specify a password on the command line because the password can be seen in a process listing. The --password is mutually exclusive with the --passwordfile option. --passwordfile=filename Specifies the file from which to obtain the password that the source machine uses for the teleporting request. The request succeeds only if the source machine specifies the same password. When you specify a file name of stdin, you can read the password from standard input. The --passwordfile is mutually exclusive with the --password option. The VBoxManage controlvm vmname plugcpu command adds a virtual CPU to the specified VM if CPU hot-plugging is enabled. ID specifies the index of the virtual CPU to be added and must be a number from 0 to the maximum number of CPUs configured. The VBoxManage controlvm vmname unplugcpu command removes a virtual CPU from the specified VM if CPU hot-plugging is enabled. ID specifies the index of the virtual CPU to be removed and must be a number from 0 to the maximum number of CPUs configured. You cannot remove CPU 0. The VBoxManage controlvm vmname cpuexecutioncap command specifies how the maximum amount of physical CPU time used by a virtual CPU. Valid values are a percentage between 1 and 100. A value of 50 specifies that a single virtual CPU can use up to 50% of a physical CPU. The default value is 100. Use this feature with caution, it can have unexpected results including timekeeping problems and lower performance than specified. If you want to limit the resource usage of a VM it is more reliable to pick an appropriate number of VCPUs. The VBoxManage controlvm vmname vm-process-priority command specifies the priority scheme of the VM process to use when starting the specified VM and while the VM runs. Valid values are: default – Default process priority determined by the OS. flat – Assumes a scheduling policy which puts the process at the default priority and with all threads at the same priority. low – Assumes a scheduling policy which puts the process mostly below the default priority of the host OS. normal – Assume a scheduling policy which shares the CPU resources fairly with other processes running with the default priority of the host OS. high – Assumes a scheduling policy which puts the task above the default priority of the host OS. This policy might easily cause other tasks in the system to starve. The VBoxManage controlvm vmname webcam attach command attaches a webcam to a running VM. Specify the webcam as the absolute path of the webcam on the host OS or as an alias. Use the VBoxManage list webcams command to obtain the webcam alias. Note that the .0 alias is the default video input device on the host OS. .1 is the first video input device, .2 is the second video input device, and so on. The order of the devices is specific to the host system. You can specify optional settings in the form of semi-colon-separated (;) name-value pairs. These properties enable you to configure the emulated webcam device. The following settings are supported: MaxFramerate Specifies the highest rate at which to send video frames to the VM. The rate is in frames per second. Higher frame rates increase CPU load, so you can use this setting to reduce CPU load. The default value is no maximum limit. This value enables the VM to use any frame rate supported by the webcam. MaxPayloadTransferSize Specifies the maximum number of bytes that the VM receives from the emulated webcam in one buffer. The default setting is 3060 bytes, which is used by some webcams. If the VM is able to use larger buffers, higher values might reduce CPU load slightly. Note that some guest OSes might not suppport higher MaxPayloadTransferSize values. The VBoxManage controlvm vmname webcam detach command detaches a webcam from a running VM. Specify the webcam as the absolute path of the webcam on the host OS or as an alias. Use the VBoxManage list webcams to obtain the webcam alias. When a webcam device is detached from the host, the host OS determines how the emulated webcam behaves. Windows hosts: The emulated webcam device is detached from the VM automatically. Mac OS X hosts that run at least OS X 10.7: The emulated webcam device remains attached to the VM and you must detach it manually by using the VBoxManage controlvm webcam detach command. Linux hosts: The emulated webcam device is detached from the VM automatically only if the webcam is actively streaming video. If the emulated webcam is inactive, manually detach it by using the VBoxManage controlvm vmname webcam detach command. The VBoxManage controlvm vmname webcam list command lists webcams that are attached to the running VM. The output shows a list of absolute paths or aliases that attached the webcams to the VM by using the VBoxManage controlvm vmname webcam attach command. The VBoxManage controlvm vmname addencpassword command provides the vmname encrypted VM with the encryption password to enable a headless start. Specify the absolute path of a password file on the host system. If filename is -, VBoxManage prompts for the encryption password. Use the --removeonsuspend option to specify whether to save the passsword or clear it from VM memory when the VM is suspended. If the VM is suspended and the password is cleared, use the VBoxManage controlvm vmname addencpassword to provide the password to resume execution on the VM. Use this feature when you do not want to store the password in VM memory while the VM is suspended by a host suspend event. You can encrypt data stored on hard disk images used by the VM. &product-name; uses the AES algorithm in XTS mode and supports 128-bit or 256-bit data encryption keys (DEK). The encrypted DEK is stored in the medium properties and is decrypted during VM startup when you provide the encryption password. Use the VBoxManage encryptmedium command to create a DEK encrypted medium. See . The &product-name; GUI prompts you for the encryption password when you start an encrypted VM. Use the following command to perform a headless start of an encrypted VM: $ VBoxManage startvm vmname --type headless Then, use the following command to provide the encryption password: $ VBoxManage vmname controlvm addencpassword vmname - Password: encryption-password The VBoxManage controlvm vmname removeencpassword command disables a specific encryption password for all encrypted media attached to the VM. ID is the password identifier for the encryption password that you want to disable. The VBoxManage controlvm vmname removeallencpasswords command disables all encryption passwords for all encrypted media attached to the VM. The VBoxManage controlvm vmname changeuartmode command changes the connection mode for the specified virtual serial port. Valid serial port values are integers that start from 1. disconnected Disconnects the device. server pipe-name Specifies the pipe name of the server. client pipe-name Specifies the pipe name of the client. tcpserver port Specifies the port number of the TCP server. tcpclient hostname:port Specifies the host name and port number of the TCP client. file filename Specifies the name of the file. device-name Specifies the name of the device. The VBoxManage controlvm vmname autostart-enabled command specifies whether to enable or disable automatically start the VM at host system boot-up. You must do some host system configuration before you can use this feature. See . Valid values are on, which enables autostart feature for the VM and off, which disables it. The default value is off. The VBoxManage controlvm vmname autostart-delay command specifies the delay in seconds before the VM starts on host system boot-up. See . The following command temporarily stops the execution of the ol7 VM. $ VBoxManage controlvm ol7 pause The following command configures shared clipboard operation for the ol7 VM. Copying of clipboard data is allowed in both directions between the host and guest. $ VBoxManage controlvm ol7 clipboard mode bidirectional , ,