DcAN I/O Interface
From eMDeeWiki
Jump to navigationJump to searchData 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:
- The I/O device shall listen for TCP/IP connections on IP port number 33001
- A maximum of 3 clients can simultaneously connect to the DcAN I/O Interface port
- All elements of each packet shall be in network byte order
The following sections define the packets that are valid for the DcAN I/O Interface
I2C Read Request
- Each element of the I2C Read Request Packet is a 16 bit unsigned integer
- The first 16 bit word of the packet represents the unique identifier and must be equal to 0x301
- An I2C Read Response Packet with the requested data will be sent back to the client in response to each I2C Read Request
| Byte Offset | Element | Notes |
|---|---|---|
| 0 | 0x301 | |
| 2 | Request ID | Arbitrary value that will be sent back in the response |
| 4 | I2C Bus ID | 0=I2C Bus 'A' 1=I2C Bus 'B' |
| 6 | # Bytes to Read | |
| 8 | I2C Address | |
| 10 | Read Mode | 0=One-time read 1=Periodic 2=On Change + Periodic |
| 12 | Periodic Read Frequency | millseconds |
I2C Read Response
- Each element of the I2C Read Response Packet is a 16 bit unsigned integer
- The first 16 bit word of the packet represents the unique identifier and must be equal to 0x302
- An I2C Read Response Packet is sent to the client in response to an I2C Read Request
| Byte Offset | Element |
|---|---|
| 0 | 0x302 |
| 2 | Request ID |
| 4 | I2C Bus ID |
| 6 | # Bytes Returned |
| 8 | Data Returned from I2C |
Send Display Data
- Each element of the I2C Read Response Packet is a 16 bit unsigned integer
- The first 16 bit word of the packet represents the unique identifier and must be equal to 0x302
- An I2C Read Response Packet is sent to the client in response to an I2C Read Request
| Byte Offset | Element |
|---|---|
| 0 | 0x302 |
| 2 | Request ID |
| 4 | I2C Bus ID |
| 6 | # Bytes Returned |
| 8 | Data Returned from I2C |
