Message Count

Associated with: Channels on advanced drivers

This status attribute displays statistics about the success, or otherwise, of communications messages (‘data packets’) transmitted over a particular channel.

The attribute displays the number of:

• Messages—A count of the messages that ClearSCADA has received and/or transmitted via the channel since the statistics were last reset, regardless of whether those messages were received successfully by the intended target communications equipment. The message count includes, if applicable, any unsolicited messages received from outstations on the channel, and any messages that ClearSCADA has broadcast to multiple outstations.
• Replies—Messages that ClearSCADA has received in response to messages that it has sent via this channel. This includes any negative replies.
• Unsolicited—Messages that outstations have sent to ClearSCADA via this channel, in order to report that they have alarms or other data awaiting retrieval.
• Timeouts—Transmission timeouts and/or the number of times that no reply has been received from an outstation or other device in response to a transmitted message.
• Errors—Any errors reported by the outstations or other devices, in response to messages transmitted via this channel. For instance, any reports of messages being corrupt.

If the Reset Statistics pick action has been used to reset the count, two entries are displayed—the lower entry lists the previous Message Count, the upper entry is ‘live’ and lists the Message Count since the pick action was last used. The period to which each Message Count applies is indicated by the channel’s Comms Statistics attribute.

Use the Message Count status attribute in conjunction with the channel’s Comms Statistics attribute to ascertain the time period for which each set of statistics applies.

To ascertain which of the above statistics might relate to a particular outstation on the channel, look at that outstation’s Comms Statistics status attribute. (Be aware that the outstation’s attribute statistics do not take into account which channel(s) were used to communicate with that outstation.)