Applies To:
  • CitectSCADA 5.20, 5.21, 5.30
Summary:
Citect does not pick the modem up and attempt to dial. The page unit shows no dial attempts, no failed attempts. Debugging the port shows no traffic attempts at all. The [dial]debug message is;

LINE_REPLY Device (0) Params (REQUEST 13, CALL UNAVAILABLE , 0)

What do these messages mean?

Also, from the syslog and in the main Kernel window, what do the following messages mean?

Attempting to free line for high priority connection to unit 'Logger06'.

Resetting all line device unusable states for Unit 'Logger05'.

 

Solution:
Messages from the Windows Telephony API (that is tapi callback results) can be displayed in the Citect main Kernel window using the [dial]debug parameter. The meaning of such debug messages are detailed below, only the most common ones are documented here. If you receive other messages not shown in this list then there is a good possibility that the Telephony API is dealing with abnormal conditions - beyond the scope of Citect.

LINE_CALLSTATE:

ACCEPTED

The call was in the offering state and has been accepted. This indicates to (monitoring) applications that the current owner application has claimed responsibility for answering the call.

BUSY

The call is receiving a busy tone. A busy tone indicates that the call cannot be completed

CONNECTED

The call has been established and the connection is made. Information is able to flow over the call between the originating address and the destination address.

DIALING

The originator is dialling digits on the call.

DIALTONE

The call is receiving a dial tone from the PSTN, which means that the network is ready to receive a dialled number.

DISCONNECTED

The remote party has disconnected from the call.

IDLE

The call exists but has not been connected. No activity exists on the call, the network is busy or waiting for answer.

OFFERING

The call is being offered to the station, signalling the arrival of a new call.

PROCEEDING

Dialling has completed and the call is proceeding through the telephone network. This occurs after dialling is complete and before the call reaches the dialled party, as indicated by ringback, busy, or answer.

LINE_REPLY:

CALLUNAVAIL

All call appearances on the specified address (modem) are currently in use.

OPERATIONFAILED

The operation failed for an unspecified or unknown reason. The modem is switched off, not plugged into serial port or genuinely failed.

RESOURCEUNAVAIL

Insufficient resources to complete the operation. For example, a line cannot be opened due to a dynamic resource overcommitment.

Tapi is unlikely to ever recover from this.

LINE_DISCONNECTMODE:

BUSY

The remote user's station is busy.

NOANSWER

The remote user's station does not answer.

NODIALTONE

A dial tone was not detected within a service-provider defined timeout at a point during dialling when one was expected.

NORMAL

This is a normal disconnect request by the remote party. The call was terminated normally. 

UNAVAIL

The reason for the disconnect is unavailable and will not become known later. The modem is probably locked up. Reset the modem.

UNKNOWN

The reason for the disconnect request is unknown but may become known later.

 

"Attempting to free line for high priority connection to Unit <I/O Device Name>" is logged when all modems are currently in use and the user has invoked the IODeviceControl function with type 7. This is a forced connection to the device and has the highest priority, and if no modems are free the I/O server will disconnect a lower priority (e.g., a normal scheduled) connection and use the modem for the forced connection.

"Resetting all line device unusable states for Unit <I/O Device Name>" is logged when a modem may be available for use but for some reason the I/O server's internal state is that it is in use - when all the modems which could be used by this device are in such a state all the internal states are reset so that the I/O server will try again to use each modem.
 

 
Keywords:
 

Attachments