Terminal I/O Status Codes

Status Message/Description

No error detected

This is the normal status code returned when a request has been carried out successfully.

Terminal disabled

The terminal needs to be enabled to carry out the request.

Cable or local modem fault

The external transmit clock has stopped.

Terminal is busy for too long

The remote device is not allowing data to be transmitted to it. The multiplexer has timed out.

Too many retransmissions

The message has been re-transmitted too many times with errors reported either by the remote device or locally.

Error in terminal response

The remote device has responded with an unrecognized or corrupted message.

No terminal response

The remote device has stopped communicating.

Loss of carrier

The modem control signal DCD has been dropped.

Transmit underrun

The multiplexer could not supply data fast enough to keep the transmitter running. With a character oriented synchronous protocol this will usually result in SYNC characters being inserted. With a bit oriented synchronous protocol the frame being transmitted will be aborted.

Invalid terminal response

The remote device has responded with a message which is invalid in the current state.

Protocol rejects request

The protocol does not handle this type of request.

Message too long

If this applies to a transmitted message then it is probably too long to be able to complete within the transmit timeout. A received message may be too long for the allocated number of receive buffers, or may take too long to complete.

Message too short

The message is less than the minimum allowed length for this protocol.

Host has stopped polling

Only used for secondary protocols. The protocol has waited too long for a poll or select from the remote device.

BCC or CRC error

A message was received with a bad checksum.

Parity or framing error

A message was received with a bad parity bit or an asynchronous character was received with a frame problem.

Address error

A message has been received containing an incorrect address. Possibly a response from a device which was not polled.

Subaddress error

The subaddress within a received message does not match the one within the corresponding poll or select.

Receiver overrun

Data was received from a port faster than the multiplexer could load it into a buffer.

No receive buffers

The multiplexer has run out of buffers for receiving data on this port.

Terminal down

This terminal is not ready to transmit or receive data.

No call established

For a protocol which makes use of virtual circuits the requested circuit is not established.

Link disconnected

For a protocol which makes use of virtual circuits the logical link which supports the circuits is down.

Link reset

For a protocol which makes use of virtual circuits the logical link which supports the circuits has been reset.

Bad control function or format

A control write was requested which is unrecognized or not allowed by the protocol.

Inconsistent control write

A control write was requested which is not appropriate at this time.

Unable to process control write

A control write was requested but the multiplexer is unable to process the request at this time (possibly due to a shortage of resources such as buffers).

Logical terminal disabled

This logical terminal must be enabled before a data may be transmitted on it.

Logical terminal down

The logical terminal is currently down and cannot have data transmitted over it.

BREAK received from terminal

For a character mode asynchronous protocol, the “break” key has been pressed.

Port test complete

This status is returned from the diagnostic module when the requested port test is complete.

No transmit buffers

There are no free transmit buffers on this port to hold and transmit this message.

Transmit length too long

There are insufficient free transmit buffers on this port to hold and transmit the whole message.

Invalid MUX terminal number

A request has been made to a terminal which has not been initialized.

Terminal not initialized

A request has been made to a terminal which has not been initialized. That is, a zcntl() request to set the terminal parameters (ZCOM_MRQCODE_TERM) has not been issued which assigns the port number this terminal is associated with.

Retryable error occurred

An internal status code used between the driver and firmware to indicate that a request should be retried at a later time.

Buffer size illegal

The message is too large and is rejected by the firmware. On the Z7200A, Z7350A and Z7400A interfaces the message size limit is up to 10,144 bytes (depending on the protocol). For the Z7300A and Z7330A interfaces the limit is 16,384 bytes.

Invalid request code

The destination of the request did not recognize the specified request code.

Illegal term type (no protocol)

The request attempted to use a protocol which has not been installed on the system.

Header size too long for buffer

The size of the header requested by the protocol for this message is larger then the available space for data in the first buffer for the message. Configure a larger buffer size.

Fragment size illegal

The protocol has requested an illegal fragment size. Fragment sizes (i.e. usually the packet size) must be even.

Terminal already enabled

A request was made to enable a terminal that was already enabled.

Terminal already disabled

A request was made to disable a terminal that was already disabled.

Statistics upload

A control write requesting protocol statistics was made. This status message contains the requested statistics.

Deferred request (internal usage)

An internal status code used between the driver and the firmware to indicate that the request will have a deferred response.