1、SMPTE RP*it72 93 W 8357403 0000400 3Tb W SMPTE RECOMMENDED PRACTICE Common Messages for Digital Control Interface RP 172-1993 Page i of 14 pages 1 Scope This practice details and defines the control message subset common messages. Common messages are used to perform certain functions common to all e
2、quipment types within a general-purpose communications channet of an interface system. This interface system shalt transport data and digital control signals between equipment utilized in the production, post-production, and/or transmission of visual and aural information. 2 Notation This practice d
3、escribes the coding of keywords and information fields (I/F) in the form as shown below. The coding “NN” represents the assigned keyword or I/F eode, in hexadecimal form. NN KEYWORD Keyword or I/F descriptive text or I/F NAME Format: Parameter description; . Parameter value coding, scate or range; P
4、arameter definitions and explanations. In the practices listed in annex B, keywords are listed numerically, in hexadecimal notation. Keyword numbers are reserved as follows: Keywords OOh - 1 Fh: Keywords 2011 - 3%: Keywords 40h - FFh: System service subset; Common message subset; Virtual machine typ
5、e-specific subset. Copyright O 1992 by the SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved July 1, 1993 SMPTE RPS372 93 8357403 0000403 032 RP 172-1993 3 Summary of keywords, mnemonics and information field (I/F) names Hex 20 2
6、1 22 23 24 25 26 27 28 29 2A 28 2c 2D 2E 2F 30 3E 3F Keyword CNOP CRESET READ I/F ITEM RESPONSE TIMELINE SOURCE STARTUP RESPONSE EXECUTE PROCEDURE DEFINE EVENT CLEAR EVENT ERROR FAILURE TIMELINE STOP TIMELINE RUN USER DEFINED EXTENSION (Mnemonic) (CNOP) (CRST) (READ) (IFRE) (TSCE) (STRE) (EXPR) (DEE
7、V) (CLEV) (CERR) (FAIL) (TSTP) (TRUNJ (UDEF) (CEXT) Hex 20 2-t 22 23 24 25 26 27 28 29 2A 28 2c 2D 2E 2F 30 3E 3F I/F name VIRTUAL MACHINE TYPE EQUIPMENT TYPE TIME STANDARD TIMELINE TIME HIGH-RES TIMELINE TIME EVENTBUFFERSTATUS VIRTUAL MACHINE STATUS FAULT STATUS USER DEFINED EXTENStON NOTE -The abi
8、lity to perform command 291, (ERROR) is mandatory for every virtual machine. EXTENSION SET Hex O0 o1 02 03 04 05 06 07 08 o9 OA OB oc OD OE OF 10 11 FF Keyword (Mnemonic) FUNCTION POLL FUNCTION RESPONSE FIELD POLL FIELD RESPONSE UPDATE CYCLE MUTE SIMULTANEOUS READ DEFINE PROCEDURE DELETE PROCEDURE R
9、ECALL PROCEDURE PROCEDURERESPONSE RECALL EVENT EVENT RESPONSE SIMULTANEOUS READ RESPONSE EXTENSION (FNPL) (FNRE) (FDPL) (FDRE) (U DAT) (CYCL) (MUTE) (SIRD) (DEPR) (DLPR) (REPR) (PRRE) (REEV) (EVRE) (SRDR) (EXEX) (Mnemonic) (VTY P) (ETY P) (TIME) (TTIM) (HTIMJ (EBST) (VMST) (FTST) (UDND) (CIEXI Page
10、2 of 14 pages SMPTE RP*372 93 8357403 0000402 T79 RP 172-1993 4 Keywords Hex 20 21 22 23 24 25 Keyword CNOP Format: CRESET Format: READ Virtual machine no operation. Directs the destination virtual machine to assume standard values of all preselectable functions. (Same status as power up). Directs t
11、he virtual machine to transmit the instanta- neous content of the specified information field. Format: NOTE - Several cI/F NAMES may be wrapped in a BEGIN/END construct. I/F ITEM RESPONSE Response to READ, UPDATE, or CYCLE commands. Format: (Length varies according to the I/F NAME) NOTE - Several cI
12、/F NAME AND pairs may be wrapped in a BEGWEND construct. TIMELINE SOURCE Format: Directs the virtual machine to select the source of the timeline. OOh INTERNAL - Internal clock ncremented by an unspecified source (“tick) O1 h EXTERNAL - External reference time STARTUPRESPONSE Format: Indicates that
13、the controlled device has been started up. 1 -byte special binary number: OOh = coldstart 01h = warmstart NOTES 1 This response is generated automatically whenever the controlled device is powered up. 2 “Coldstart“ means that all internal stores are cleared; all functions are set to their default co
14、nditions. Page 3 of 14 pages SMPTE RP*372 93 Ba 8357403 0000403 905 RP 172-1993 26 EXECUTE PROCEDURE Format: 27 DEFINE EVENT Format: Directs the virtual machine to execute immediately the procedure name. NAME is in the range 01h to FFh. OOh is reserved. Prepares an event; i.e., a function which shal
15、l be executed at the instant of coincidence of a specified trigger time with the content of a specified I/F time. 8-blts Specifies the function. NOTES 1 In order to implement a procedure in an event, EXECUTE PROCEDURE shall be used for the COMMAND, and the procedure shall have been predefined. 2 The
16、 TRIGGER SOURCE I/F NAME is a TIMELINE or a type-specific time information field. 3 All iunctions contained within a procedure defined as an event must be executed by the virtual machine at the trigger time specified by the event. 4 The virtual machine shall clear an event on execution. 5 The EVENT
17、NAME is unique for each event. 6 Where mutually exclusive commands are given inadvertently at the same tirne through the use of events constructs, such events shall be cleared by the virtual machine and an error message returned. 28 CLEAR EVENT Clears one or all events previously established. Format
18、: ( is all events) 29 ERROR Format: Advises the controlled virtualmachine that the previous string has not been understood by or cannot be performed by the controlled virtual machine. 8-bi t: O0 = Parse error. O1 = Cannot do by design. 02 = Insufficiently equipped. 03 = Buffer overflow. 04 = Invalid
19、 keyword. 05 = Invalid keyword argument. FE = See FAULT STATUS information field for more information. FF = Unspecified a-bits, not including the byte count. Truncated not to exceed an overall ERROR message length of 256 bytes. Page 4 Of 14 pages SMPTE RP*l72 93 m 8357403 0000404 841 m R P 172-1 993
20、 2D FAILURE Format: 2F TIMELINE STOP Format: 30 TIMELINE RUN Format: 3E USER DEFINED Format: CRAW DATA 3F EXTENSION Warns of a catastrophic failure of the specific machine; i.e., a failure which requires intervention by the local operator. If the timeline is internal, stops the timeline from increme
21、nting. If the timeline is internal, starts the timeline incrementing from the time indicated. (type TIME) Identifies USER DEFINED commands. 16-bit binary unsigned number. Specifies the length of the command, in bytes, not including the byte count itself. (Length varies according to the byte cou nt .
22、) Directs the virtual machine to enter the common message extension set for the following single command only. The virtual machine shall then resume execution of the basic command set. Format: (1 or more bytes) EXTENSION SET RESERVED O0 o1 02 Page 5 of 14 pages RP 172-1993 03 FUNCTION POLL SMPTE RP*
23、i172 93 E 8357403 0000405 788 Format: 04 FUNCTION RESPONSE Format: 05 FIELD POLL Format: 06 FIELD RESPONSE Page 6 of i 4 pages Directs the virtual machine to indicate which of the keywords contained in the command set are supported by its type-specific machine. BEGIN and END are excluded from the ke
24、ywords. The existence of the function poll command assumes the existence of the BEGIN/END construct. Contains the list of supported keywords in response to a FUNCTION POLL command. Directs the virtual machine to indicate which I/F names contained in the parameter list are supported by the type-speci
25、fic machine information field. Contains the list of supported I/F names from those indicated in a FIELD POLL command. Format: - SMPTE RP*372 73 E 8357403 00004Ob b34 = O7 UPDATE Format: RP 172-1993 Directs the virtual machine to respond immediately with fhe contents of the information field, and the
26、n automaticatly whenever its contents change. NOTES 1 The single may be replaced by several names wrapped into a BEGIN/END construct. 2 The defaulf condition is MUTEd. 3 When an information field value has changed a number of times in the period between bus-confrolter polls, only the most recent val
27、ue is transmitted at the next poll. 08 CYCLE Directs the virtual machine to transmit periodically, as specified, the instantaneous contents of the specified information field. Format: (type TIME) (Hex) NOTES I The single cI/F NAME may be replaced by several names wrapped in a BEGINEND construct. 2 T
28、he default condition is MUTEd. 3 When an information field value has changed a number of times in the period between bus-controller polls, only the most recent value is transmitted at the next poll. O9 MUTE Format: OA SIMULTANEOUS READ Format: Directsthe virtual machine to switch off all responses p
29、reviously initiated by CYCLE or UPDATE commands. Directs the virtual machine to read simultaneously the contents of the specified information fields. Page 7 of i4 pages SMPTE RP*372 93 IH 8357433 O000407 550 RP 172-1993 OB oc OD OE DEFINE PROCEDURE Format: Directs the virtual machine to assemble a b
30、lock of virtual machine commands for subsequent execution. (Hex) in the range 61 h - FFh. ooh is reserved. 16-bits, not including the byte count. The procedure. NOTES 1 All functions contained within a procedure which is used within an event must be executed by the virtual machine at the trigger tim
31、e specified by the event, even if actions must be taken in advance. 2 Procedures are retained until receipt of a DELETE PROCEDURE or CRESET command. DELETE PROCEDURE Format: RECALL PROCEDURE Format: PROCEDURERESPONSE Directs the virtual machine to delete a command block previously defined. (Hex) (oo
32、h deletes ail procedures) Directs the virtual machine to transmit, but not execute or delete, the specified procedure for checking purposes. (Hex) (OOh recalls all procedures) Response to RECALL PROCEDURE command. Format: 16-bits, not including the byte count. Page 8 of 14 pages OF RECALL EVENT SMPT
33、E RPs172 43 8357491 0000408 497 RP 172-1993 Format: Causes an EVENT RESPONSE from the controlled virtual machine containing the data of an event already established. (OOh recalls all events) 10 EVENT RESPONSE Contains the data of an event already established. Format: (type TIME) Function caused by t
34、rigger condition. 11 SIMULTANEOUS READ RESPONSE Response to SIMULTANEOUS READ with all specified information fields: Format: FF EXTENSION Directs the virtual machine to enter the further extension set for the following single command only. The virtual machine shall then resume execution of the basic
35、 set. Format: Page 9 of 14 pages SMPTE RPM372 93 8357403 0000409 323 RP 172-1993 5 Information fields 20 RESERVED 21 VIRTUAL MACHINE TYPE Contains the virtual machine name and hence defines the type-specific machine command set. Format: (8-bit binary unsigned number) NOTE - The content of VIRTUAL MA
36、CHINE NAME shall be defined explicitly in each virtual machine dialect; the virtual machine name for a wholly USER-DEFINED virtual machine is O1 h. 22 EQUIPMENT TYPE Contains the data to identify the specific product, i ncl u d i n g hard war elsof twar e rev is ion I eve I. Format: 8-bit binary uns
37、igned number: 0011 is undefined 01 h is “48“ 02h S “50“ 0311 is “60“ 24 TIMELINE TIME Contains the timeline time value. Format: 25 HIGH-RES TIMELINE TIME Stand ar d “ti me“ f o r m at. Contains the time of a high-resolution timeline where applicable. Format: 6 - byte express i on i n “ h i g h - re
38、s o I ut i o n ti m e“ form a t. Page 1 O of 14 pages SMPTE RP*kL72 93 8357YOL 00004LO 045 U? 172-1993 26 27 29 3E EVENTBUFFERSTATUS Tallies the event buffer status. Format: h = OFF 0th = not availabte 021, = available FAULT STATUS Tallies faults in the system and their reasons where detected by int
39、ernal diagnostics (as applicable). Format: 1-byte number specifying the number. n of parameter groups following: . l-byte code 1 st detected 1-byte number - fault 1 -byte code nth detected 1 -byte number - fault NOTES 1 Parameter group count = O means: no fault. 2 The error codes and faulty item num
40、bers are user-defined. USER DEFINED Identifies USER DEFINED information fields. Format: 3F EXTENSION Format: 16-blt binary unsigned number. Specifies the length of the information field in bytes, not including the byte count itself. (Length varies according to the byte counf.) Directs the virtual ma
41、chine to enter the common message i/F name extension set for the following single I/F name only, The virtual machine shall then resume access to the basic I/F name set. Page 11 of 14 pages SMPTE RP*372 93 E! 357403 0000413 TL RP $72-1 993 Annex A (informative) General concepts The following text con
42、tains a general explanation of some of the concepts used in the formulation of the common message set. It constitutes tutorial information and is intended to assist in the understanding of the specifications in previ- ous portions of this practice. A.1 Commands and responses The message language is
43、subdivided into two varieties of message which differ only in the direction of information flow between controlling and controlled virtual machines. -COMMANDS are messages from a controlling to acontrolled virtual machine; - RESPONSES are messages from a controlled to a control- ling virtual machine
44、; responses are generally transmitted in reaction to a command. A.2 State machine and information transfer The virtual machine controlled by the message language is considered to be a STATE MACHINE. The message set can be regarded as being of two types: - Messages which change the state of the virtu
45、al machine (e.g., the VTR messages STOP and PLAY). These commands reside mainly in the type-speciic message set and comprise commands which are mutually exclusive (e.g., the tape motion commands VMCs in the VTR set); -Messages (commands and responses) which do not change the state, but which only ca
46、rry information to or from the virtual machine. As information transfer is a general requirement of all types of virtual machines, general principles are applied to these tasks; therefore, these messages reside mainly in the common message set. A.3 Information flelds (IF) Items of information which
47、are maintained by and held within a controlled virtual machine, and which may be needed by its controlling virtual machine, are arranged in a virtual array of INFORMATION FIELDS, in a manner similar in concept to a data base. Each information field is identified by a unique descriptor called the INF
48、ORMATION FIELD NAME. This name, coded as a binary value, is used as an address within all commands referencing the field. Therefore, the information field name is used as a parameter name in these commands. The format of information field data within each message, as transmitted over the remote cont
49、rol system, is predefined for each item by the information field name. Each message set requires its own array of information fields. The complete field array of a specific virtual machine comprises the field array specified in the common message set, together with that of the type-specific message set. A typical example of a command requiring an information field is READ, which directs the virtual machine to transmit the content of one or more information fields: as specified Page 12 of 14 pages within the command. The SIMULTANEOUS READ com- mand directs the
