A group terminal block describes the groups on a USB device. It exists only for USB. When a device has function blocks, use them instead to find its active groups, names, and more, and you can usually ignore its group terminal blocks. To learn more, see MidiFunctionBlock.
Note: Windows MIDI Services turns each “port” on a MIDI 1.0 device into its own group terminal block. Each virtual cable number, which used to become a separate input or output port, now becomes a group number. For example, a MIDI 1.0 device with 5 ports shows up as one endpoint with 5 group terminal blocks, each covering one group.
Properties
| Property |
Description |
Number |
The block number |
Name |
The name from the USB descriptors. For a MIDI 1.0 device, this is the iJack string, if the device has one |
Direction |
Which way messages go, from the block’s point of view |
Protocol |
Which protocol the block uses. Ignore the jitter reduction values here. Jitter reduction timestamps are agreed on during protocol negotiation, and the service handles them completely |
FirstGroup |
The first group this block covers |
GroupCount |
How many groups this block covers |
MaxDeviceInputBandwidthIn4KBitsPerSecondUnits |
The device’s maximum input bandwidth from the USB descriptors, in units of 4 kilobits per second. See the USB MIDI 2.0 specification for details |
MaxDeviceOutputBandwidthIn4KBitsPerSecondUnits |
The device’s maximum output bandwidth from the USB descriptors, in units of 4 kilobits per second. See the USB MIDI 2.0 specification for details |
CalculatedMaxDeviceInputBandwidthBitsPerSecond |
MaxDeviceInputBandwidthIn4KBitsPerSecondUnits, worked out in bits per second |
CalculatedMaxDeviceOutputBandwidthBitsPerSecond |
MaxDeviceOutputBandwidthIn4KBitsPerSecondUnits, worked out in bits per second |
Functions
| Function |
Description |
IncludesGroup(group) |
Returns true if this block covers the group |
AsEquivalentFunctionBlock() |
Returns a MidiFunctionBlock that’s roughly the same as this block, so your application only has to deal with one kind of block when it shows this information |
Static Properties
| Static Property |
Description |
ShortLabel |
The short name for a group terminal block in the user’s language |
ShortLabelPlural |
The plural of the short name |
LongLabel |
The full name in the user’s language |
LongLabelPlural |
The plural of the full name |
