The VS protocol analyzer has to have knowledge of the nodes on the bus, which support the VS protocol. The VS protocol analyzer has to know the following information of a node, which support the VS protocol:
| • | its name, |
| • | the assigned channel number, |
| • | the transmit offset and length, this specify the time slot the node may transmit asynchronous stream packets, |
| • | the receive offset and length, this specify the time slot the node can aspect to receive asynchronous stream packets, |
| • | and the datapump offset and length, this specifies the time slot the node may transmit datapump packets. |
This information of a node is to be provided manually in the 'Protocol Analyzer Settings' dialog or via an import file.
Open 'Protocol Analyzer Settings' dialog
Click the toolbar button 'Settings' to open the 'Protocol Analyzer Settings' dialog, see figure below.
The information of the nodes, which support the VS protocol, is to be added in the table 'VS Channels' of the VS tab page. Click on the VS tab to show the VS tab page on top.
table VS Channels
Each row in table 'VS Channels' represents a node. The table shows in the columns the specific information of a node. This specific information of a node is: its name, the channel number, the heartbeat and the time slots to transmit an asynchronous stream packet, to receive an asynchronous stream packet and to transmit a datapump packet.
There are 2 procedures defined to add information of one or more nodes into table 'VS Channels'. The first procedure uses button 'New' to add information into the table 'VS Channels' and the second procedure uses an import file to load information into the table 'VS Channels', see as an example import file VSDefinitions.csv.
add information of one or more nodes
manually
Click button 'New' to add a row to table 'VS Channels' and provide for each column the specific information.
Import file
Click button 'Import' to open the dialog 'Open' and select the import file (e.g. VSDefinitions.csv). The information included in the import file will be loaded into table 'VS Channel'.
The extra features of the VS tab page are described below.
remove information of a node
Click the row in table 'VS Channel' to select it. This will also enable button 'Remove'. Click button 'Remove' to remove the selected row from table 'VS Channel'.
margin of the time slots
The margin of the time slots is adjustable via spin box 'Margin'. The margin has effect on the start time and the end time of a time slot, see figure below.
The default value of margin is 60 microseconds.
extended error checking
Click the check box 'Enable extended check' to enable the check boxes: 'Check heartbeat', 'Check vertical parity' and 'Check message payload length'.
Click the check box 'Check heartbeat' to enable error checking of the heartbeat value of the nodes, which support the VS protocol. During analysis of a VS packet the VS protocol analyzer will first check if the heartbeat value of the node, which generated the VS packet, has increased. The field 'Heartbeat' of the VS packet contains the heartbeat value of the node. If the heartbeat value has increased the heartbeat value of the node is valid. If the heartbeat value of the node didn't increased the VS protocol analyzer checks if the frequency by which the heartbeat value increase doesn't fall below the minimum heartbeat frequency. If this is the case, a heartbeat error occurred.
Click the check box 'Check vertical parity' to enable error checking of the field 'Vertical Parity Check' of the VS packets.
Click the check box 'Check message payload length' to enable error checking of the field 'Message Payload Length' of the VS packets.