Common Items

Overview

These object items are available for Devices and Connection Objects through OPC.

Common Object Items

To access these items you must click on the object itself and not the Protocol/Standard/Extended Items.

Item	Data Type	Description
ActiveItems	I4	The total number of items active or advised to this device.
AllPollReset	Bool	Clears all of the "Total" poll statistics items.
Barometer	I4	An indicator of the communication status on the primary and secondary connections Note: The communications barometer represents the marginal success rate of communications. For each poll cycle that does not receive a response for one or more poll messages, the barometer will increase by two (2), with a maximum value of 100. For each poll cycle that does receive a valid response for all poll messages, the barometer to decreases by 1, with the lowest value being 0. These barometer changes cause failures in communications to show up quickly as the barometer rises. However, good communications must be maintained longer and more steadily for the barometer to fall back to 0.
CommStatus	I2	Represents the status of the communication link to the device. The value will be 1 if a communication link to the device can be established – even if the device does not respond to polls. The value will be 0 if a communication link cannot be established to the device.
IncompletePoll	Bool	Set to false at the beginning of each poll. The value changes from false to true if the last poll attempt was incomplete.
ItemCount	I4	The number of items that have been added by OPC clients.
LastPollAttemptTime	Date	The date time stamp of the last poll attempt.
LastPollAttemptTimeUTC	Date	The date time stamp of the last poll attempt in UTC (without time zone bias).
LastPollFailureCode	I4	An integer value indicating the result of the last poll. 0 = Success 1 = No poll initiated 2 = Error opening connection 3 = Error during modem initialization 4 = Connection failed 5 = Line is busy 6 = No answer 7 = Connection was dropped
LastPollLength	I4	The length of time (in seconds) between the beginning of a poll cycle and the successful completion of said poll cycle.
LastPollSuccessTime	Date	The date time stamp of the last successful poll.
LastPollSuccessTimeUTC	Date	The date time stamp of the last successful poll in UTC (without time zone bias).
MinutesSinceComplete	I4	Minutes since the last complete poll.
ScanIntervals	I4	Bitmask of intervals that the device is currently polling.
Scanning	Bool	This item is true when the object is scanning.
SecondsSinceComplete	I4	Seconds since the last complete poll.
Status	I2	An integer value indicating the result of the last poll. 0 = Starting 1 = Complete 2 = Incomplete 3 = Interrupted 4 = Communication error 5 = Failed 7 = Port is Closed or Disabled
StatusDesc	String	Descriptive result of the last poll. "Starting" "Complete Poll" "Incomplete Poll" "Interrupted Poll" "Communication Error" "Failed Poll" "Port is Closed or Disabled"
TimeSinceComplete	I4	Time (in minutes) since the last complete poll.

Timespan-Based Common Object Items

Substitute the appropriate available duration LastHour, ThisHour, Today, Total, or Yesterday for <Timespan> in each of the available items in the table below. Each of the items in the table below is available for five different time periods where <Timespan> is one of the following time periods:

LastHour
ThisHour
Today
Yesterday
Total

Example 1: For the number of Bad Responses in the last hour add ObjectName.LastHourBadResponses where ObjectName is replaced with your actual device or port name.

Example 2: For the number of Bad Responses in this hour add ObjectName.ThisHourBadResponses where ObjectName is replaced with your actual device or port name.

Example 3: For Bad Responses today, add the item ObjectName.TodayBadResponses where ObjectName is replaced with your actual device or port name.

Example 4: For the number of Bad Responses yesterday, add the item ObjectName.YesterdayBadResponses where ObjectName is replaced with your actual device or port name.

Example 5: For the total number of Bad Responses, add the item ObjectName.TotalBadResponses where ObjectName is replaced with your actual device or port name.

Item	Data Type	Description
<Timespan>BadResponses	I4	The number of bad responses.
<Timespan>CharReceives	I4	The total number of bytes received on the primary and secondary connections.
<Timespan>CharSend	I4	The total number of bytes sent in poll messages on the primary and secondary connections.
<Timespan>CommNoInits	I4	For serial based connections, the total number of times the port could not be opened or setup. For socket based connections, the total number of times the socket could not opened or connected.
<Timespan>CommNoOpens	I4	The number of times a port could not be opened or a socket could not be created.
<Timespan>CommRetries	I4	The total number of times poll messages were due to be sent on the primary and secondary connections, but the connection module could not access, or connect to, the required resource (such as a serial port) in the selected <timespan>. Note: The CommRetries represent the number of times a connection module could not access or open the connection link. For serial connections, this is simply the specified serial port. For dialup connections, this is the specified serial port and/or the modem connection to the device. For connection modules that offer a 'connection retries' configuration parameter, the CommFail item is also used. This item represents the number of times a connection was attempted for each 'connection retry' and no connection could be made.
<Timespan>CRCs	I4	The total number of CRC, checksum, or other validation checks, that failed on the primary and secondary connections.
<Timespan>Errors	I4	The number of polls that resulted in a protocol error.
<Timespan>GoodResponses	I4	The number of good responses.
<Timespan>Interruptions	I4	The number of times a poll was interrupted by a higher priority task.
<Timespan>NoPolls	I4	The number of times a poll was not started when it was due (such as when a device is disabled or not licensed).
<Timespan>NoResponses	I4	The total number of poll messages that did not receive a valid response to any of the poll attempts on the primary and secondary connections.
<Timespan>PartialPolls	I4	The number of times a device was polled but received good responses on only some of its requests.
<Timespan>PctBadTries	R4	The percentage of polls that did not get a good response. PctBadTries = 100 * (Bad Tries / (Queries + Retries))
<Timespan>PctErrors	R4	The percentage of polls that resulted in a protocol error. PctErrors = 100 * (Error Responses / Queries)
<Timespan>PctFirstTries	R4	The percentage of good responses to first tries. PctFirstTries = 100 * (First Try Responses / Queries)
<Timespan>PctGoodPolls	R4	The percentage of complete poll cycles. PctGoodPolls = 100 * (Complete Polls / Poll Attempts)
<Timespan>PctGoodResponses	R4	The percentage of good responses without regard to whether the response came from a query (the first request) or a retry. PctGoodResponses = 100 * (GoodResponses / Queries)
<Timespan>PctGoodTries	R4	The percentage of good responses calculated from all tries (queries and retries). PctGoodTries = 100 * (GoodResponses / (Queries + Retries))
<Timespan>PollAttempts	I4	The number of polls that were initiated.
<Timespan>Poll Reset	I4	(Only available for: “This Hour” and “Today” Timespans)
<Timespan>PollSuccesses	I4	The number of polls that completed with good responses to all data requests.
<Timespan>Queries	I4	The total number of poll messages sent, not including retries, on the primary and secondary connections. Only the first transmission of the message is a “Query”. If no response comes from the device within the allotted time, the message is sent again (up to a configured maximum number of times) – this re-send is a “Retry”.
<Timespan>Retries	I4	The total number of times poll messages were re-sent (due to a reply time-out or other error) on the primary and secondary connections.
<Timespan>Timeouts	I4	The total number of reply time-outs to poll messages on the primary and secondary connections.
<Timespan>Transmits	I4	The number of messages sent through the port.
<Timespan>Unsoliciteds	I4	The number of times a device called in or initiated a poll request.