ARC_STO¶
| Parameter | Value |
|---|---|
| Library_File_Name | ARCNET_AC500_V12.lib |
| Firmware | V1.2 |
| Type | Type_Function_Block_History |
| Group | Data |
During the transmission of a data package, the success of the transmission is monitored by an adjustable timeout period. When this time is exceeded, distinctive information of the data package is stored in the timeout buffer.
These are:
- the NODE ID of the receiver (4 bytes)
- the length of the involved data packet
- header data of the involved data set.
The length of the timeout buffer as well as the number of user data to be stored can be set for the ARCNET processing in the PLC configuration of the Control Builder. The buffer is constructed as a circular buffer (FIFO). If the buffer is full, the oldest entry in the buffer is overwritten. If the ARC_STO Function Block is enabled by EN = TRUE, it checks whether a data packet is stored in the buffer and provides the user with the above mentioned information as of the variable given at input DATA. At the outputs NODE_ID and LEN, the NODE ID and the original length of the telegram, which could not be sent, are available.
Before the ARC_STO Function Block can be used, the setting “ARCNET data exchange” has to be selected. Additionally, the input TOUT of the ARC_SEND Function Block must be >0.