A request was made to a device address that does not exist. For example, an attempt was made to read register number 4000 when there are only 200 registers in the device.

The server canceled the command while the driver was processing it. This can happen if the driver takes too long to process the command. Check the timeout and retries for the driver.

A request was made specifying a data type not supported by the protocol. This error will not occur during normal operation.

A request contains invalid data; for example, writing to a floating-point address with an invalid floating-point number. Check the CitectSCADA database.

The server sent a command to the driver that it did not recognize. This error will not occur during normal operation.

The communication channel is not performing normally, and is causing errors in the transmitted data.

A device is not responding to read or write requests. The driver sent a command to the device and the device did not respond within the timeout period.

Unmapped driver specific errors are normally reported as a general error. Refer to the protocol-specific errors listed with the protocol you are using.

A write operation was attempted to a location that is protected against unauthorized modification. Change the access rights to this location to permit a write operation.

The communication channel, server, or device hardware is not performing normally. Examine hardware components. The server's operation needs to also be examined for proper operation.

The communication link between the server and the device is functioning correctly; however, the device is experiencing an error or is in a non-operational state, for example, the device is in program mode.

The device is in offline mode, preventing any external communication. This error will cause any stand-by units to become active. CitectSCADA will attempt to re-initialize the unit.

An internal software error has occurred in the driver. This error should not occur during normal operation.

An attempt has been made by an unauthorized user to access information. Check the user's access rights.

The server or driver has run out of memory and cannot continue execution. Minimize buffer and queue allocation or expand the server computer's memory (physical or virtual memory).

There are no communication buffers left to allocate. The performance of the server may be reduced; however, it can still continue to run. Increase the number of communication buffers.

This error may occur in periods of high transient loading with no ill effects. If this error occurs frequently, increase the number of communication buffers.

Too many commands have been sent to the driver.

The server is not receiving any response from the driver. This error should not occur during normal operation.

Each driver can only support a fixed number of communication channels. You have exceeded the limit. The command or data request has not been completed.

A communication channel is currently offline, disabling communication. The server cannot initialize the communication channel or the channel went offline while running. Every device (units)connected using this channel will be considered to be offline so this will cause any stand-by devices to become active. CitectSCADA will attempt to re-initialize the channel.

The server has attempted to communicate using a channel that is not open.

The server is attempting to communicate with a channel that has not been initialized. This error should not occur during normal operation. The command or data request has not been completed. If the condition persists, contact support.

A channel has too many devices attached to it. This error should not occur during normal operation.

The data requested is not in a valid format or expected type.

The server tried to cancel a command, but the driver could not find the command. This error should not occur during normal operation.

Communication has been switched from the primary to the stand-by unit(s). The server returns this message when a hot changeover has occurred.

A response was longer than the response buffer. If this error occurs on serial communication drivers, garbled characters may be received. Check the communication link and the baud rateThe number of times per second a signal changes in a communication channel. While the baud rate directly affects the speed of data transmission, the term is often erroneously used to describe the data transfer rate. The correct measure for the data rate is bits per second (bps). of the driver.

There is a configuration error, for example invalid special options have been set.

There is an error in a stand-by unit.

There is no response from the communications server.

Cannot talk with remote unit (for example dial-up I/O Devices). Only used for scheduled I/O Devices.

The driver is performing the action requested, but needs to notify of a potential issue. For example, some drivers may use this to alert you to stale data.