The messages in the following sections are logged to the BASEstar Classic history file by the DAS for Modicon programmable controllers. These messages are logged to provide more detailed diagnostic information than what is supplied by the returned status values.

Messages logged to the history file for DAS for Modicon programmable controllers use event class 21 and event type 24.

To view all messages logged by this DAS use the following syntax:

$ BSTAR BSTAR> SHOW HISTORY/EVENT=21.24.*

B.1 Modbus NI Logged Messages

The following messages are logged by the Modbus Network Interface (NI).

Disconnected station #!SL on port !AD.
Explanation: Informational. The device at the port and station address has successfully been disabled.
User Action: None.

Hang up message received for port !AD.
Explanation: Informational. If the port is a LAT port, then either the network connection to the terminal server has been broken or the serial line connection to the PLC has been disconnected. If the port is a TT port, then the serial connection to the PLC has been disconnected.
User Action: If the cause of the hangup was a network disconnection, then determine the cause of the network disconnection (could be physical problems with the network or the terminal server was powered down) and correct the problem. If the cause of the hangup was the port, then check for broken or missing cables and correct any problems found.

Station #!SL is being removed.
Explanation: Informational. The station is being disconnected due to a hangup on the line.
User Action: None.

QIO error.
Explanation: Error. An error occurred when reading or writing data to the port.
User Action: Examine the error message and take action based on the error found. If connected via a terminal server examine the terminal server counters for errors as well. Check cabling for improper length, improper grounding, breaks, etc.

Purged !UW bytes from port !AD.
Explanation: Informational. The current response from the port is being discarded because a different device responded to the request than the one requested, or the checksums do not match.
User Action: If connected via a terminal server examine the terminal server counters for errors. Check cabling for improper length, improper grounding, breaks, etc.

Unexpected reply from station #!UB, Expected station #!UB.
Explanation: Error. A different programmable controller responded to a request than the one expected. This problem could be the result of a faulty controller or because of a faulty cable.
User Action: Check cabling for improper length, improper grounding, breaks, etc. If cabling checks out, then replace the controller.

Checksums did not match - retries exceeded.
Explanation: Error. The received checksum did match the calculated value and retries have been exceeded.
User Action: Check cabling for improper length, improper grounding, breaks, etc. If using a terminal server, check the port counters for errors.

B.2 Modbus Plus NI Logged Messages

The following messages are logged by the Modbus Plus Network Interface (NI).

Disconnected station !AD.
Explanation: Informational. The DAS has successfully aborted the connection to the device.
User Action: None.

Routing byte !UL value !AD invalid.
Explanation: Error. The indicated part of the route is not a number or is not a valid number.
User Action: Modify the network address to be a valid sequence of numbers in xx-xx-xx-xx-xx format.

QIO error when reading slave command for path !UB.
Explanation: Error. A QIO error occurred when reading from the indicated slave path. A slave path is used for reading unsolicited commands (read or write) from the device.
User Action: Examine the error returned and take action based on the error found.

QIO error when writing slave response for path !UB.
Explanation: Error. A QIO error occurred when writing to the indicated slave path. The error occurred when attempting to respond to a command that had been sent to the host.
User Action: Examine the error returned and take action based on the error found.

QIO error when writing master command for path !UB.
Explanation: Error. A QIO error occurred when writing to the indicated master path. A master path is used for writing solicited commands (read or write) to the device.
User Action: Examine the error returned and take action based on the error found.

QIO error reading master response for path !UB.
Node type: !UB, error condition: !UB.
Explanation: Error. A QIO error occurred when reading from the indicated master path. A master path is used for writing solicited commands (read or write) to the device. See Modicon DEC Host Based Devices User's Guide for a description of error condition codes.
User Action: Examine the error returned and take action based on the error found.

Insufficient routing bytes in slave write request from source address !UB.
Explanation: Error. The DAS has been configured to expect routing bytes in the message sent on a slave path to the host and less than 5 words of data were sent. The source address is valid only if the programmable controller is on the closest Modbus-Plus network.
User Action: Correct the program in the programmable controller to send the required routing information as well as the data or reconfigure the DAS to not expect routing information in the data. See Section 2.3.4.2 for information on configuring the DAS to not expect routing information in the data.

Rejected slave write request from undefined slave network address !AD.
Explanation: Error. A slave write request was received that was assumed to contain routing information in the first five words, but the routing information did not match any configured device.
User Action: Modify the programmable controller program to identify its own address in the first five words of data that are sent or reconfigure the DAS to not expect routing information in the data. See Section 2.3.4.2 for information on configuring the DAS to not expect routing information in the data.

No unsolicited response block available, request discarded.
Explanation: Error. A request from the device was received, but the queue of unsolicited I/O blocks has been exhausted.
User Action: Increase the size of the queue by increasing the value of the parameter ILAN$MOD984_UNSOL_QUEUE_SIZE or ILAN$MODHOST_UNSOL_QUEUE_SIZE, as appropriate. See Section 2.3.4.2 for more information on these parameters.

Rejected slave read request from source address !UB, no host device defined.
Explanation: Error. A read request was received, but no host device has been configured. It is also possible that the request was received soon after startup and the DAS has not yet been informed of the host device. The source address is only valid for the closest Modbus Plus network.
User Action: Configure a host device to receive unsolicited read requests.

Rejected slave write request from source address !UB, no host device defined.
Explanation: Error. A write request was received, but no host device has been configured. It is also possible that the request was received soon after startup and the DAS has not yet been informed of the host device. The source address is only valid for the closest Modbus Plus network.
User Action: Configure a host device to receive unsolicited write requests or reconfigure the DAS to not send write requests to the host device. See Section 2.3.4.2 for information on configuring the DAS to not send data to the host device.

Rejected function code !UB from source address !UB, unsupported function.
Explanation: Error. A modbus function other than "READ HOLDING REGISTERS", function code "3", or "PRESET MULTIPLE REGISTERS", function code "16", was received by the DAS. These two modbus functions are the only two functions supported by the DAS. The source address is only valid for the closest Modbus Plus network.
User Action: Reprogram the programmable controller to send a supported modbus function code.

HOST address !AD already configured (only one host allowed).
Explanation: Error. A host device has already been configured for this Modbus-Plus communications card. Only one host device is allowed per Modbus-Plus communications card.
User Action: Delete this device.

B.3 Modbus TCP/IP NI Logged Messages

The following messages are logged by the Modbus TCP/IP Network Interface (NI).

Sub-net byte #!UB is invalid.
Explanation: Error. The indicated part of the sub-net address is not a number or is not a valid number.
User Action: Modify the network address to be a valid sequence of numbers in xx.xx.xx.xx format.

A device with this network address has already been defined.
Explanation: Error. An attempt was made to define duplicate network addresses.
User Action: Either delete the other device with the same address or use a different network address for this device.

Error when disconnecting from a socket.
Explanation: Error. An error occurred when attempting to disconnect from the socket using the QIO function IO$_DEACCESS | IO$M_SHUTDOWN.
User Action: Examine the error to determine the cause of the failure and take action based on the error found. See Digital TCP/IP Services for OpenVMS System Services and C Socket Programming for information on Digital TCP/IP Services for OpenVMS services.

Error when creating a socket.
Explanation: Error. An error occurred when creating a socket using the QIO function IO$_SETMODE.
User Action: Examine the error to determine the cause of the failure and take action based on the error found. See Digital TCP/IP Services for OpenVMS System Services and C Socket Programming for information on Digital TCP/IP Services for OpenVMS services.

Error when setting a socket option.
Explanation: Error. An error occurred when setting a socket option using the QIO function IO$_SETMODE. Socket options being set are PROBE_TIME and DROP_TIME.
User Action: Verify that the values in the BASEstar Classic parameters ILAN$MODTCP_PROBE_TIME and ILAN$MODTCP_DROP_TIME are valid values. See Section 2.3.4.3 for a discussion of these parameters. See Digital TCP/IP Services for OpenVMS System Services and C Socket Programming for information on Digital TCP/IP Services for OpenVMS services.

Error when connecting to a socket.
Explanation: Error. An error occurred when connecting to a socket using the QIO function IO$_ACCESS.
User Action: Examine the error to determine the cause of the failure and take action based on the error found. See Digital TCP/IP Services for OpenVMS System Services and C Socket Programming for information on Digital TCP/IP Services for OpenVMS services.

Rejecting connection from !UB.!UB.!UB.!UB.
Explanation: Error. The DAS has just received a connection request and there is no device defined with the network address of the incoming connection.
User Action: Create and enable a device with the network address of the incoming connection or reprogram the programmable controller with that address so that it no longer tries to connect to the host.

Write QIO error when writing to a socket.
Explanation: Error. An error occurred when writing to a TCP/IP socket.
User Action: Examine the error to determine the cause of the failure and take action based on the error found. See Digital TCP/IP Services for OpenVMS System Services and C Socket Programming for information on Digital TCP/IP Services for OpenVMS services.

Read QIO error when reading from a socket.
Explanation: Error. An error occurred when reading from a TCP/IP socket.
User Action: Examine the error to determine the cause of the failure and take action based on the error found. See Digital TCP/IP Services for OpenVMS System Services and C Socket Programming for information on Digital TCP/IP Services for OpenVMS services.

Rejected function code !UB, unsupported function.
Explanation: Error. A modbus function other than "READ HOLDING REGISTERS", function code "3", or "PRESET MULTIPLE REGISTERS", function code "16", was received by the DAS. These two modbus functions are the only two functions supported by the DAS.
User Action: Reprogram the programmable controller to send a supported modbus function code.

Matching transaction not found for invocation id !UW (timed out).
Explanation: Error. A response was received from the device, but a request with a matching transaction number (invocaton ID) was not found. The most likely cause for this error is that the request timed out and was deleted.
User Action: Increase the I/O timeout (on the path definition) or analyze the network to identify and eliminate bottlenecks in order to improve network response times.

No unsolicited response block available for inv id !UW - discarded.
Explanation: Error. A request from the device was received, but the queue of unsolicited I/O blocks has been exhausted.
User Action: Increase the size of the queue by increasing the value of the parameter ILAN$MOD984_UNSOL_QUEUE_SIZE. See Section 2.3.4.2 for more information on this parameter.

Network address !AD connection lost.
Explanation: Error. The DAS received a connection failed, or timeout status from the network. The DAS starts aborting the connection to the device.
User Action: Determine the cause of the network disconnection and then reconnect to the device.

Network address !AD connection established.
Explanation: Informational. The DAS has successfully established a TCP/IP connection to the device.
User Action: None.

Network address !AD disconnected.
Explanation: Informational. The DAS has successefully disconnected the TCP/IP connection to the device.
User Action: None.