Comtrol UP DeviceMaster User Guide - Manual (Page 89)

DeviceMaster UP Modbus/TCP User Guide: 2000447 Rev. I Chapter 4. Diagnostic and Statistics Pages - 89
Communication Statistics
To PLC Dropped
Packet Count
Displays the number of received serial packets intended for the PLC dropped:
• No STX byte(s) found
• No ETX byte(s) found
• Time-outs
• Packet to large
• Receive buffer queue overflows
To PLC Truncated
Displays the number of received packets that were truncated before being sent to the
PLC.
Tx Unexpected
Seq Errors
Displays the number of Unexpected Transmit Sequence Number errors. The
DeviceMaster UP increments this number when the following statements are true:
• You enabled the Transmit Sequence Number Checking configuration option. (See
Attribute 16 - Serial Port Transfer Options on Page 22 for additional information.)
• DeviceMaster UP receives a transmit message with a sequence number that is not
equal to either the previous transmit sequence number or the previous transmit
sequence number plus one. (The DeviceMaster UP expects this sequence number to
be incremented by one with each new transmit message.)
Rx Con Seq Errors
Count
Displays the number of received consumed sequenced number errors. The DeviceMaster
UP only increments this number when all of the following statements are true:
• You selected the Write-to-Tag-Sync method of receive communication.
• DeviceMaster UP receives a serial packet.
• The Consumed Sequence number is out of sync. (It is not equal to the Produced
Sequence number or equal to the Produced Sequence number minus one.)
Tx Duplicate Seq
Errors
Displays the number of Duplicate Transmit Sequence Number errors. The DeviceMaster
UP increments this number when the following statements are true:
• You enabled the Transmit Sequence Number Checking configuration option. (See
Attribute 16 - Serial Port Transfer Options on Page 22 for additional information.)
• DeviceMaster UP receives a transmit message with a sequence number equal to the
previous sequence number. (The DeviceMaster UP expects this sequence number to
be incremented by one from the sequence number in the previous transmit message.)
Serial Device Interfaces Statistics (Continued)