Communication between system and operator

The system and its users have the option of sending messages to the consoles and receiving responses from them, where the “user” can also be an operator who is himself sitting at a console. By their nature, the contents and meaning of these messages are very diverse. To distinguish which messages to handle in which way, they are distinguished by types and attributes.

Types of message

To enable the recipient to tell as soon as possible what type and priority of message is involved, the system splits them up into types. All messages output at the console are assigned to one of these types and has a unique type identifier which is output with it.

The following types of message are defined:

%	“Message”: Information message to be noted by the operator.
?	“Query”: Message which requires a response.
.	“Response”: Response by the operator to a query.
;	“Instruction”: Message which the operator is asked to do something. From the internal point of view of the system, instructions are also questions, but differ in that the response cannot be given by the operator, but only by the sender of the query.
/	“Command”: Type identifier for the entry of a command.
+	“Command result”: Message from a command server to the sender of the command.
&	“Additional command information request”: Message in which the sender of a command is asked to enter further information.
:	“Additional command information”: Response by the issuer of the command to a additional command information request.
!	“Command termination”: Message which the person who enters the command is informed of the end of runtime monitoring by the system. This is normally identical with the termination of the command, but there are exceptions. For more details, see the section "Command termination messages".
*	“Rejection”: Message with which UCON rejects an errored entry. All possible rejections are set out in section "Return messages on physical and virtual consoles".

Message attributes

Certain other attributes of a message, not always apparent from the type, are also crucial for the system's message handling mechanisms and commands. The following properties are distinguished:

• “response” and “non-response” messages

• “command-linked” and “non-command-linked” messages

• “directed” and “non-directed” messages

Response and non-response messages

All messages of the following type are “response”:

• query

• request for additional command information

• instruction

All messages of all other types are “non-response”.

This message attribute is important, for instance, on output, where response messages are highlighted (on color screens, e.g. red instead of green) and can be redisplayed with the SHOW-PENDING-MSG command.

Command-linked and non-command-linked messages

All messages of the following types, including the command itself, are “command-linked”:

• command result

• request for additional command information

• additional command information

• command termination

All messages of all other types are “non-command linked”.

This message attribute is important when programming command servers for special operator commands (see "Special operator commands in authorized user programs"). 

Directed and non-directed messages

“Directed” messages are directed to a precisely defined recipient.

In contrast, “non-directed” messages have a routing code specified as the recipient. They are distributed by the system to all consoles that contain the specified routing code - this may be a large number or none at all.

Unlike the other message attributes, the message type here is not a unique criterion: responses (to the person making the query) and all command-linked messages are indeed directed, but the other types of message may be both directed and non-directed. This can be reliably identified only in the CONSLOG, where the recipient of each message is logged at the same time, and in authorized user programs that contain their messages in expanded form (see "Authorized user programs with operator functions").

Emergency messages are treated here in a special way. For technical reasons they are initially directed to the main console. Then, where still possible, they are distributed on a non-directed basis via the routing code *, but only to virtual consoles, not to physical ones.

This message attribute is important, e.g. in message filtering (ADD-/REMOVE-CONSOLE-FILTER commands). This mechanism affects only undirected messages with message type “%” (message). 

Output format

All messages are provided with a uniform, 17-character prefix on output to a console. Exception: responses to queries from the operator have no time specification

Column 1	Message type identification: for possible value, see "Communication between system and operator"; Exception: only “?” and “Y” for emergency messages
Columns 2-5	Sender of the message; possible notations: (mn): Sender is the physical console with the MN “mn” name: Sender is the virtual console with the authorization name “name“ tsn: Sender is the task with the TSN “tsn”
Column 6	Hyphen (minus sign)
Columns 7-9	Message job ID: three-digit, alphanumeric message identification
Column 10	Separator: If the system parameter SECSTART=N is specified, the separator is always a period. If SECSTART=Y is specified, the separator is a “#” if the message originates from the system itself, and is thus “trusted”. Other messages, e.g. output by the user with INFORM-OPERATOR, have a period as a separator.
Columns 11-16	Time in the format: hhmmss (in the case of responses, the response text starts in column 11).
Column 17	Blank
Columns 18ff	Text of message

Example

% 6C5-000.122342 % BLS0519 PROGRAM 'EDT' LOADED