mbus HFCE Packet At Index.vi
Description
The HFCE Packet At Index is an advanced function to extract HFCE Messages out from corrupted HFCE data.
Refer to HFCE Message At Index to extract HFCE Messages from valid HFCE data.
Using HFCE Packet At Index in a loop parses the hfceMsgs into individual messages. The hfceMsgs represents the received buffer for HFCE data. It is composed of successive 16-bit words, supposedly coding for label, payload size, N data words and so on. With HFCE Packet At Index, messages are separated one from the next based on the hardware packets delimiters (preamble and postamble), and not based on the payload size words, that could be corrupted.
For example:
Received hfceMsgs shows:
| hfceMsgs word # | 16-bit word |
|---|---|
| Index #0 | 0x00AA (message 1's label) |
| Index #1 | 0x0007 (corrupted payload size) |
| Index #2 | 0x0011 (data 0) |
| Index #3 | 0x0022 (data 1) |
| Index #4 | 0x0033 (data 3) |
| Index #5 | 0x00BB (message 2's label) |
| Index #6 | 0x0004 (payload size) |
| Index #7 | 0x1100 (data 0) |
| Index #8 | 0x2200 (data 1) |
| Index #9 | 0x3300 (data 3) |
| Index #10 | 0x4400 (data 4) |
By using mbus HFCE Packet At Index in a loop, returned HFCE messages are:
| Message #0 | 16-bit word |
|---|---|
| Label | 0x00AA |
| Payload size | 0x0007 |
| Data word #0 | 0x0011 |
| Data word #1 | 0x0022 |
| Data word #2 | 0x0033 |
| Message #1 | 16-bit word |
|---|---|
| Label | 0x00BB |
| Payload size | 0x0004 |
| Data word #0 | 0x1100 |
| Data word #1 | 0x2200 |
| Data word #2 | 0x3300 |
| Data word #3 | 0x4400 |
The corrupted payload size has no impact.
| Parameters | ||
|---|---|---|
| error in | in | error conditions that occur before entering the function |
| hfceMsgs | in | HFCE receive messages |
| wordCount | in | number of HFCE words received |
| msgIndex | in | start index of the HFCE message to decode |
| packetSize | in | HFCE packet size |
| label | out | HFCE message label |
| payloadSize | out | HFCE payload data size in 16-bit words |
| nextMsgIndex | out | start index for the next HFCE message |
| packet | out | HFCE packet |
| payloadData | out | HFCE payload data |
| error out | out | error information |
| function return | out | function execution status |
Availability
Available in Multibus VI 1.0 and later.
See Also
Examples
HFCE Error Injection and Detection.vi HFCE Send Receive Advanced.vi