Available Free Memory - BCPro - LIT-12011908 - General System Information - BCPro System - 4.0

MS/TP Communications Bus for the BCPro System Technical Bulletin

Brand
BCPro
Product name
BCPro System
Document type
Technical Bulletin
Document number
LIT-12011908
Version
4.0
Revision date
2020-03-16
Language
English

Free memory is required to buffer all incoming and outgoing messages, as well as to save information needed for internal processing. If available free memory becomes low, some communications fail and devices may drop offline. If available free memory becomes completely depleted, all processing fails.

If the free memory available is low, received BACnet® protocol messages (starting with the lowest priority) are aborted (discarded if in the Alarm or Critical state). The Protocol Engine counter, Rcv Messages Discarded (under BACnet Protocol Eng, Diagnostic tab), displays the number of discarded messages. Additionally, BACnet protocol messages waiting to be transmitted are also discarded. If an external node is waiting for a reply, an abort is sent unless the condition is alarm or critical. The number of aborted messages are counted and displayed in Abort Tx (under BACnet Protocol Eng, Diagnostic tab). The Protocol Engine counter, Tx Messages Discarded (under BACnet Protocol Eng, Diagnostic tab), displays the number of discarded messages. If this state exists for more than a few seconds, external BACnet protocol devices may be flagged offline.

If the free memory available is at the alarm level or worse, checking for the online/offline status of external BACnet protocol devices stops. This may cause external BACnet protocol devices to be flagged offline if they are not frequently sending data to their supervisory device.

If the free memory is critical, messages to be routed from one network to another through the controller are discarded. Additionally, information for routing to previously unknown network numbers are not saved. BACnet protocol messages received from the IP port are discarded. The IP port counter, Discarded Frames (under Eth IP Datalink, Diagnostic tab), displays the number of messages received and discarded by the IP port.