View source for DcAN I/O Interface

Data can be passed between a client and a DcAN I/O device through the DcAN I/O Interface.  Packets are sent through a TCP/IP port.  The following rules apply:
<ul>
<li>The I/O device shall listen for TCP/IP connections on IP port number 33001</li>
<li>A maximum of 3 clients can simultaneously connect to the DcAN I/O Interface port</li>
<li>All elements of each packet shall be in network byte order</li>
</ul>

The following sections define the packets that are valid for the DcAN I/O Interface


==I2C Read Request==
<ul>
<li>Each element of the I2C Read Request Packet is a 16 bit unsigned integer</li>
<li>The first 16 bit word of the packet represents the unique identifier and must be equal to 0x301</li>
<li>An I2C Read Response Packet with the requested data will be sent back to the client in response to each I2C Read Request</li>
</ul>


{| style="text-align:center"

|-
! width="100" bgcolor="#CCCCCC" |Byte Offset
! width="220" bgcolor="#CCCCCC" |Element
! width="320" bgcolor="#CCCCCC" |Notes

|-
! bgcolor="#CCCCCC" |0
| bgcolor="#FFBBBB" |0x301
| bgcolor="#CCCCCC" |
|-
! bgcolor="#CCCCCC" |2
| bgcolor="#FFBBBB" |Request ID
| bgcolor="#CCCCCC" |Arbitrary value that will be sent back in the response
|-
! bgcolor="#CCCCCC" |4
| bgcolor="#FFBBBB" |I2C Bus ID
| bgcolor="#CCCCCC" |0=I2C Bus 'A'<br>1=I2C Bus 'B'
|-
! bgcolor="#CCCCCC" |6
| bgcolor="#FFBBBB" |# Bytes to Read
| bgcolor="#CCCCCC" |
|-
! bgcolor="#CCCCCC" |8
| bgcolor="#FFBBBB" |I2C Address
| bgcolor="#CCCCCC" |
|-
! bgcolor="#CCCCCC" |10
| bgcolor="#FFBBBB" |Read Mode
| bgcolor="#CCCCCC" |0=One-time read<br>1=Periodic<br>2=On Change + Periodic
|-
! bgcolor="#CCCCCC" |12
| bgcolor="#FFBBBB" |Periodic Read Frequency
| bgcolor="#CCCCCC" |millseconds

|}

==I2C Read Response==
<ul>
<li>Each element of the I2C Read Response Packet is a 16 bit unsigned integer</li>
<li>The first 16 bit word of the packet represents the unique identifier and must be equal to 0x302</li>
<li>An I2C Read Response Packet is sent to the client in response to an I2C Read Request</li>
</ul>


{| style="text-align:center"

|-
! width="100" bgcolor="#CCCCCC" |Byte Offset
! width="280" bgcolor="#CCCCCC" |Element
|-
! bgcolor="#CCCCCC" |0
| bgcolor="#FFBBBB" |0x302
|-
! bgcolor="#CCCCCC" |2
| bgcolor="#FFBBBB" |Request ID
|-
! bgcolor="#CCCCCC" |4
| bgcolor="#FFBBBB" |I2C Bus ID
|-
! bgcolor="#CCCCCC" |6
| bgcolor="#FFBBBB" |# Bytes Returned
|-
! bgcolor="#CCCCCC" |8
| bgcolor="#FFBBBB" |Data Returned from I2C

|}

==I2C Write==
<ul>
<li>The first 10 bytes of the I2C Write Packet are 16 bit unsigned integers</li>
<li>The first 16 bit word of the packet represents the unique identifier and must be equal to 0x303</li>
</ul>


{| style="text-align:center"

|-
! width="100" bgcolor="#CCCCCC" |Byte Offset
! width="220" bgcolor="#CCCCCC" |Element

|-
! bgcolor="#CCCCCC" |0
| bgcolor="#FFBBBB" |0x303
|-
! bgcolor="#CCCCCC" |2
| bgcolor="#FFBBBB" |Request ID
|-
! bgcolor="#CCCCCC" |4
| bgcolor="#FFBBBB" |I2C Bus ID
|-
! bgcolor="#CCCCCC" |6
| bgcolor="#FFBBBB" |# Bytes to Write
|-
! bgcolor="#CCCCCC" |8
| bgcolor="#FFBBBB" |I2C Address
|-
! bgcolor="#CCCCCC" |10...
| bgcolor="#FFBBBB" |Bytes to be Written

|}

==Write Display Pixel Data==
<ul>
<li>The first 14 bytes of the Write Display Data Packet are 16 bit unsigned integers</li>
<li>The first 16 bit word of the packet represents the unique identifier and must be equal to 0x304</li>
</ul>


{| style="text-align:center"

|-
! width="100" bgcolor="#CCCCCC" |Byte Offset
! width="280" bgcolor="#CCCCCC" |Element
|-
! bgcolor="#CCCCCC" |0
| bgcolor="#FFBBBB" |0x304
|-
! bgcolor="#CCCCCC" |2
| bgcolor="#FFBBBB" |I2C Bus ID
|-
! bgcolor="#CCCCCC" |4
| bgcolor="#FFBBBB" |I2C Address
|-
! bgcolor="#CCCCCC" |6
| bgcolor="#FFBBBB" |Beginning Pixel Column
|-
! bgcolor="#CCCCCC" |8
| bgcolor="#FFBBBB" |Beginning Pixel Row
|-
! bgcolor="#CCCCCC" |10
| bgcolor="#FFBBBB" |Total Number of Pixel Columns
|-
! bgcolor="#CCCCCC" |12
| bgcolor="#FFBBBB" |Total Number of Pixel Rows
|-
! bgcolor="#CCCCCC" |14...
| bgcolor="#FFBBBB" |Array of Pixel Columns and Rows (8 pixels per byte)

|}