Bradley Smoker PLC-5 user manual Monitoring Data Sent with Acknowledgment

9-8Communicating with Devices on a DH+ Link

Monitoring Data Sent with Acknowledgment

Status Field	Word(s)	Description
Received	19	Number of error-free SDA messages that the station received.
Received SAP off	23	Number of SDA messages that the station received but could not process because its service
		access point (SAP) was off.
		This counter should always be 0.
Received but full	22	Number of SDA messages that the station could not receive because of lack of memory.
Received with error	20	Number of invalid SDA messages that the station received. Some causes are:
		bad CRC
		the message has an invalid source address
		the message has an unrecognizable control byte
		the transmission was aborted
		This counter indicates noise; increase the cable’s shielding from noise.
Received retransmissions	21	Number of times the sending station re-transmitted an SDA message, which was ACKed or
		NAKed
		If node sends a message but does not receive an ACK or a NAK response, the node will
		re-transmit the message. If a node retransmitted a message because the acknowledge response
		to the first message was lost, the node receiving the message detects the retransmission and
		sends an acknowledge response. But the receiving node discards the duplicate message. High
		counts of this counter indicates noise or cable problems; check that the cable is secure and
		properly shielded from noise.
Transmit failed	29	Number of SDA messages sent by the station that were determined to be in error. This counter is
		the sum of the SDA transmit not ACKed and SDA transmit timeout counters.
Transmit timeout	26	The number of SDA messages that were sent but not ACKed or NAKed by the receiving station
		This counter increments even if the message does get through during a retry and if the receiving

station is unable to communicate. This counter indicates a noise or a cabling problem (the receiving station is not seeing the messages).

Publication 1785-UM012D-EN-P - July 2005