Acknowledgments

• Overview

• Message Format

• Acknowledgment Code

• Configuring Acknowledgments

Overview

An acknowledgment is a short reply from the NE indicating that an input command message is being acted upon or has been immediately rejected. The essential purpose of an acknowledgment is to reassure a human user that a command

that takes a long time to execute has been received by the NE.

An acknowledgment is later followed by an output response message to the command. However, in some circumstances,an acknowledgment is the only output message triggered by a command. An acknowledgment should be used if an output response message to the command cannot be transmitted within two seconds of its receipt.

Message Format

The format of an acknowledgment is as follows:

where,

acknowledgment code : Identifies the reason for the acknowledgment.

CTAG : Identifies the associated input command.

(<) character : The acknowledgment terminator.

Acknowledgment Code

The valid values for acknowledgment code and their meanings are given below.

1. IP - In Progress and PF - Printout Follows
   
   The request has been initiated. These acknowledgments should produce output messages that give a termination report or a termination report and results of the command. They are used often for test and access messages requiring a long execution time. These acknowledgments are often followed by either Completed or Denied response messages.

2. OK - All Right
   
   The command was received and the requested action was initiated and completed. In addition, OK is used in response to a command that has been cancelled by inclusion of the CAN (Cancel) character.

3. NA - No acknowledgment
   
   This command is sent if initiation or execution of the requested command is not possible. Under abnormal conditions,NA is sent when command has been accepted but control of the processing has been lost. It can also be used to respond in circumstances if the command is garbled during transmission. If the CTAG value of the command could not be determined, then Zero(0) should be used as a ctag value for the acknowledgment.

4. NG - No Good ( Not Used )
   
   The command is valid but the requested action conflicts with current system or equipment status. For inadequate system resources use RL instead of NG. This acknowledgment code is seldom used because specific error code in output response messages can be employed to signify the same information. It can be used if desired.

5. RL - Repeat Later
   
   The requested action cannot be executed due to unavailable system resources caused by system overload, excessive queue lengths, busy programs, etc. The command can be sent at later time for any response.

6. No - No acknowledgment message is configured.

Configuring Acknowledgments

To configure acknowledgment message for a command,

• Select the required command code from the loaded command set file ( as .tcs file or .prp configuration file format ).

• Select the Access ID and Message Payload value from the list, for which acknowledgment must be configured.

• Select the required acknowledgment Message from the values listed in the combo box.