3.2.3 Card Connection |
Connecting one or multiple card(s) to the Process Data Analyzer API shows some behavior that might need additional explanation.
Suggested IP on DiscoveryThe Discover command returns a list of all found devices and their CardInfos. These get the SuggestedIpFieldNumber field set by the server. The suggested IP is determined automatically by pinging all available card IPs. A responding IP address is set and the IPv6 address is preferred over an IPv4 address.
Connecting a Card by Serial NumberCurrently the actual connection to a card is always done by the card's IP address. If a connection by serial number is desired, the service will check if it can map the serial number to a known IP address of a card. If none is found, a discovery will be done to look for a fitting card on the PC or the network. The result of the discovery will be cached for as long as the service is running but the initial discovery might take a while and can slow down the connection process. If this is an issue in your application, please connect to your card(s) by IP address.
Order of Connected Cards and their ConfigurationsThe IP used to connect a card is set as the ConnectionId by the service on connection. This ID is used to map the CardConfigurations to each card without relying on any unique card property like the serial number. It allows for an easy swapability of a connected card without any changes to the configurations, if the new card gets assigned the same IP address as the previous card and is connect with this IP.
If a card is connected by serial number, the ConnectionId will be auto deduced to the SuggestedIp.