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 PS 3.5. 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 9.3-13 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 which 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.