Specifications

7 Document History
• Version 0.2 (Feb 23, 2009):
– Julian day (JDAY) changed to mean Julian day (MJD).
– Fixed error in specification of left- vs. right-justification.
– Pointed out in the definition of MPM that a UT day can have have a leap second.
– More specific guidance for MIB labels (allowable characters, lengths, etc).
• Version 0.3 (Mar 20, 2009):
– Fixed error in representation of MJD.
– Fixed error in which MCS-RESERVED MIB labels “SUBSYSTEM” and “SERIALNO”
were both index 1.4.
– Settled on use of UDP over TCP. References to TCP have been removed.
– Maximum size of a packet payload set to 4050 bytes.
– The field “DATALEN” has been added to indicate the length of the DATA field.
– MJD and MPM now are now interpreted simply as the time at which the message is sent.
Specification of times at which commands are to become effective, or for which responses
indicate the observed conditions, must be indicated separately in the data field.
– Added a new field “CKSUM”, which is a CRC32 checksum for the packet payload.
– The DATA field of response messages has been standardized to include an explicit indi-
cation of accept/reject by the controlled subsystem.
– Clarified policy on use of multi-packet messages.
– Using single quotes (’) in place of periods (.) to represent spaces in command-response
examples.
• Version 0.4 (Mar 29, 2009):
– INFO (MIB index 1.2) contains MIB labels (not indices) to elaborate on MI B index 1.1.
– Some editing intended to untangle the use of the terms “message”, “packet”, and “pay-
load”.
– “Multipacket” messages are no longer an option. References to NPKTS and INDEX have
been removed.
– Fixed errors in RPT response examples. Also modified examples to reflect above change.
– Included some guidance on the meanings of the “MJD” and “MPM” fields.
– Standardized response times to all messages to be within 3 seconds.
– Clarified that subsystems must ignore messages that have invalid checksum, or which are
not addressed to it or “ALL”.
– Edited description of “SERIALNO” field.
• Version 1.0 (Apr 4, 2009):
– Maximum message length increased from 4050 bytes to 8192 bytes.
– Removed CKSUM field from message format. Examples updated accordingly.
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