DICOM PS3.7 2019b - Message Exchange

9.3.5 C-ECHO Protocol

The information necessary for the C-ECHO request and indication DIMSE-C primitives are conveyed in the C-ECHO-RQ Message. The information necessary for the C-ECHO response and confirmation DIMSE-C primitives are conveyed in the C-ECHO-RSP Message.

9.3.5.1 C-ECHO-RQ

The C-ECHO-RQ Message contains fields as defined in Table 9.3-12. Each field shall conform to DICOM encoding and Value Representation as defined in PS3.5. Fields are required as specified in the C-ECHO service definition unless otherwise noted in Table 9.3-12. Fields not specified in the C-ECHO service definition but present in Table 9.3-12 are required by the DIMSE-C protocol.

Table 9.3-12. C-ECHO-RQ Message Fields

Message Field

Tag

VR

VM

Description of Field

Command Group Length

(0000,0000)

UL

1

The even number of bytes from the end of the value field to the beginning of the next group.

Affected SOP Class UID

(0000,0002)

UI

1

SOP Class UID associated with this operation.

Command Field

(0000,0100)

US

1

This field distinguishes the DIMSE-C operation conveyed by this Message. The value of this field shall be set to 0030H for the C-ECHO-RQ Message.

Message ID

(0000,0110)

US

1

Implementation-specific value that distinguishes this Message from other Messages.

Command Data Set Type

(0000,0800)

US

1

This field indicates that no Data Set is present in the Message and shall be set to a value of 0101H.


DICOM PS3.7 2019b - Message Exchange