XENTRA 4900 communication protocol
Supported device types and versions
Communication line configuration
Communication station configuration
I/O tag configuration
Literature
Changes and modifications
Document revisions
| Kotva | ||||
|---|---|---|---|---|
|
...
Communication supports reading data from Servomex XENTRA 4900 devices.
| Kotva | ||||
|---|---|---|---|---|
|
...
| Kotva | ||||
|---|---|---|---|---|
|
...
- Communication protocol: Servomex XENTRA.
- Station address is not used (one XENTRA device is being connected on the line)
...
The following station protocol parameters can be defined:
Table 1
| Keyword | Full name | Meaning | Unit | Default value |
|---|---|---|---|---|
| WT | Wait Timeout | Delay between individual line readings. | ms | 1000 |
| MWR | Max Wait Retry | Repetition count of line readings when the message is not completed yet. | - | 15 |
| XT | XENTRA Time | I/O tag value time allocated from received message (YES) or from PC (NO). | YES/NO | NO |
| SC | START CODE | Transmitted string containing object values (data frame) begins with the binary code of 0x01 (start code). Setting the parameter to NO disables searching for the start code. The setting is required by newer versions of the XENTRA device firmware. | YES/NO | YES |
String containing the protocol parameters is being defined as follows:
...
| Kotva | ||||
|---|---|---|---|---|
|
...
Possible I/O tag types: Ai (Analog Input) or TiA (Absolute Time Input).
Example of received data message:
...
From the message format implies, that individual items are semi-colon separated (;) - it defines I/O tag addressing. In the tab Address of the I/O tag configuration dialog box, there is required one number - item index in the data packet. Index is defined as a decimal number from 1 (or as a hexadecimal number with a hash at the beginning, e.g. #0A). It means that the index of 1 contains the item 14-07-97, the index of 5 contains the item 20.95, the index of 8 contains the item 6.2, etc.
Ai type: there can be used just the indexes (addresses) of I/O tags, which can be converted to a real number. In the example above: indexes (addresses) of 3,5,8,11,14,17 and 20 (their values are: 6.0, 20.95, 6.2, 3.5, 0.2, 0.0 and 0.0). If the item can't be converted to a real number, the I/O tag value is invalid.
TiA type: there can be configured only one I/O tag of TiA type - the index (address) of 0. The I/O tag get the time and date from the items of the indexes of 1 and 2. In the example above - it is the value of 16:15:32 14-07-1997.
...