SMPTE RP 163-1992 Television - System Service Messages.pdf

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1、SMPTE RP*1b3 92 U 8357YOL 0000315 74b ai SMPTE RECOMMENDED PRACTICE for Television - System Service Messages RP 163-1 992 Page 1 of 11 pages 1 Scope This practice details and defines the control message subset for the system service level. System service messages are used to perform system functions

2、 within a general-purpose communications channel of an interface system. This interface system shall 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 describes the c

3、oding of keywords and information fields (I/F) in the form shown below. NN KEYWORD Keyword or I/F descriptive text The coding NN represents the assigned Other comments .I keyword or I/F code in hexa- decimal format or I/F NAME “trib-” Descriptive text: effect of message at tributary. “bc-” Descripti

4、ve text: effect of message at bus controller. Format: Parameter description; . Parameter value coding, scale or range; Parameter definitions and exptanations In the practices listed in annex B, keywords are listed numerically in hexadecimal notation. Keyword numbers are reserved as follows: - Keywor

5、ds OOh - 1 Fh: System service subset - Keywords 20h - 3Fh: Common message subset - Keywords 40h - FFh: Virtual machine type-specifc 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 September 1,1992

6、SMPTE RP*lb3 72 0 8357LiOl 00003Lb 682 El RP 163-1992 3 Summary of keywords, mnemonics and information field (I/F) names Hex Keyword m ne mon ic) O0 SYSTEM SERVICE NO OPERATION (SNOP) O1 Reserved for BEGIN (RBGN) 02 Reserved for END (REND) 03 SYSTEM SERVICE RESET (SRST) 04 INITIAL SEGMENT (ISGT) 05

7、SUBSEQUENT SEGMENT (SSGT) 06 BLOCK (BLCK) 07 VIRTUAL MACHINE/GROUP SELECT (VMGS) 08 SYSTEM SERVICE ERROR (SERR) O9 VIRTUAL GROUP ATTACH (VGAT) OA VIRTUAL GROUP DISCONNECT (VGDT) OB oc OD OE OF 10 ASSIGN LINKAGE (ALNK) 11 DEASSIGN LINKAGE (DLNK) 12 ASSIGN SUPERVISORY (ASGP) 13 DEASSIGN SUPERVISORY (D

8、SGP) 14 ASSIGN VIRTUAL GROUP (AVGP) 15 DEASSIGN VIRTUAL GROUP (DVGP) 16 BC READ (BCRD) 17 BC I/F ITEM RESPONSE (BtRE) 18 REQUEST TIME TRANSMISSION (RQTT) 19 BUS CONTROLLER USER DEFINED (BCUD) IR 1B IC 1D 1E 1F EXTENSION (SEXT) LEVEL GROUP LEVEL GROUP Hex I/F name 10 LINKAGE 11 STATUS ( m n e m o n i

9、 c) (LINK) (STAT) 12 SUPERVISORY LEVEL (SGRP) 13 VIRTUAL GROUP (VGRP) GROUP 14 15 16 17 18 19 1A 1B 1c ID 1E FF EXTENSION NOTES - 1 Information field names 03h - OFh are resewed. 2 The following convention is used in all messages (system service, common, and type-specific): - most-significant byte (

10、MSB) is transmitted first; - least-significant bit (Isb) is transmitted last. Page 2 of 11 pages (SIEX) RP 163-1992 4 Keywords 00 SYSTEM SERVICE NO OPERATION trib- and bc- System service no operation. Relayed by bc. Format: O1 Reserved for BEGIN 02 Reserved for END These codes are reserved for BEGIN

11、 and END delimiters. They are used in the form: Relayed by bc. 03 SYSTEM SERVICE RESET trib- System service reset. Resets all system service level functions to the power-up default state: Virtual machine select - O Virtual groups disconnected Segmentation off. bc- Select virtual circuit O for the ad

12、dressed tributary. Sent by bc. Format: 04 INITIAL SEGMENT trib- Directs the system service level to commence segment assembly. bc- Do not parse message further. Relayed by bc. Format: 8-bit binary unsigned number; count zero is the final segment. NOTE -The final byte of a data segment shall be the f

13、inal byte of a supervisory level message block. 05 SUBSEQUENT SEGMENT trib- Directs the system service level to continue segment assembly. bc- Do not parse message further. Relayed by bc. Format: . 8-bit binary unsigned number; count zero is the final segment. NOTES - 1 The final byte of a data segm

14、ent shall be the final byte of a supervisory level message block. 2 A tributatywith multiple virtual machines attached must provide separate segmentation facilities for each virtual machine. t Page 3 of 11 pages SMPTE RP*363 92 E3 8357403 0000338 455 RP 163-1992 06 BLOCK trib- Directs the system ser

15、vice level to disassemble messages which have been concatenated within a single supervisory level message block. The BLOCK command shall be employed to delimit messages on every occasion where message concatenation is employed. bc- Looks at end of block for system service message. Relayed by bc. For

16、mat: 8-bit binary unsigned number. Specifies the length of the individual blocked message, in bytes, not including the byte count. , 07 VIRTUAL MACHINE/GROUP SELECT trib- Directs the system service level to select the specified virtual machine or group. bc- Selects the virtual circuit linkage for th

17、e indicated virtual machine. Format: 8-bit binary unsigned number in the range ooh - EFh (machine), Foh- FFh (group). OOh is default. 08 SYSTEM SERVICE ERROR trib- and bc- Advises that the system service command in the last frame received had not been understood, or could not be performed. Following

18、 detection of a SYSTEM SERVICE ERROR condition, no further processing will take place on the supervisory level frame, although any virtual machine message(s) encountered up to that point will still be forwarded to their destinations. Relayed by bc. Format: 8-bit O0 - parse error O1 - cannot do by de

19、sign 02 - insufficiently equipped 03 - buffer overflow 04 - invalid keyword argument 05 - destination tributary unavailable 8-bits; not including the byte count Page 4 of 11 pages SMPTE RPzLb3 92 W 8357401 0000319 391 W RP 163-1992 O9 VIRTUAL GROUP ATTACH trib- Directs the system service level to at

20、tach the specified virtual machine to the specified virtual machine group. bc- Never received. Sent by bc. Format: 8-bit binary unsigned number in the range 8-bit binary unsigned number in the range h to FFh Only. h to EFh. ooh iS default. OA VIRTUAL GROUP DISCONNECT trib- Disconnects the specified

21、virtual machine from the specified virtual machine group. bc- Never received. Sent by bc. Format: as VIRTUAL GROUP ATTACH OOh removes all group assignments for a particular virtual machine. 10 ASSIGN LINKAGE Format: 11 DEASSIGN LINKAGE Format: as ASSIGN LINKAGE trib- Never received. bc- Directs the

22、bus controller system service level to esfabtish a unidirectionat linkage. Where SOURCE = Supervisory level select address + virtual machine number (default is OOh); and DESTINATION = Supervisory teve1 select address + virfual machine number or virtual group number (default is OOh) or DESTINATION =

23、Supervisory level group select address + virtual group number (default is OOh). trib- Never received. bc- Directs the system service level to terminate the specified unidirectional tinkage. Page 5 of 11 pages SMPTE RP*:L63 92 8357401 0000320 003 161 RP 163-1 992 12 ASSIGN SUPERVISORY trib- Never rec

24、eived. the designated group. LEVEL GROUP bc- Directs the bus controller to assign a tributary to Format: 13 DEASSIGN SUPERVISORY trib- Never received. LEVEL GROUP Format: as ASSIGN SUPERVISORY GROUP bc- Directs the bus controller to remove a tributary from a designated group. 14 ASSIGN VIRTUAL GROUP

25、 trib- Never received. bc- machine to a virtual group. Where MACHINE = Tributary sefect Directs the bus controller to assign a virtual Format: address + virtual machine number. 15 DEASSIGN VIRTUAL GROUP trib- Never received. bc- Directs the bus controller to remove a virtual machine from a virtuai g

26、roup. Format: as ASSLGN VIRTUAL GROUP 16 BCREAD Format: trib- Never received. bc- Direct-s the bus controCCer to transmit the instantaneous contenfs of the information field. Note-The I/F NAME may be replaced by several names wrapped in a BEGIN/END construct. 17 BC I/F ITEM RESPONSE trib- Contains t

27、he VF data in response to a BC READ command. bc- Never received. Format: Note- Several I/F NAMESNALUES may be wrapped in a BEGIN/END construct. Page 6 of 11 pages SMPTE RP*1b3 92 E! 8357403 0000321 T4T W RP 163-1992 18 REQUEST TIME TRANSMISSION trib- Never received. bc- Directs the bus controller to

28、 transmit the value of the master system clock to all virtual machines using the common message TIMELINE RUN. Format: 19 BUS CONTROLLER USER DEFINED trib- Never received. bc- Directs the bus controller to enter the user defined command state. On entry to such a state the specific bus controller pars

29、es the data bytes which follow. This wit be manufacturer-, operator-, and/or instaltation- dependent. Format: 8-bit binary unsigned number. Specifies fhe length of the command in bytes, not including the byte count itsetf. CRAW DATA IF EXTENSION trib- and bc- Directs the tributary or bus controller

30、to enter the extension command set for the following single command only. They shall then resume execution of the basic command set. Format: (one or more bytes 5 Information fields 10 LINKAGE Format: . D EST IN AT I ON Contains all the linkage information. Where SOURCE = Supervisory level select add

31、ress + virtual machine number and DESTINATION = Supervisory level select address + virtual machine number or virtual group number (default is ooh) or DESTINATION = Supervisory level group select address + virtual group number (default is ooh). When necessary, the linkage information may be segmented

32、. (default is h); Page 7 of 11 pages I SMPTE RPsLb3 92 c9 8357403 0000322 986 RP 163-1 992 11 STATUS Format : Tallies the system service levei status. OOh: Linkage directory established; clock available O1 h: No linkage directory; clock available iOh: Linkage directory established; no clock availabl

33、e 1 It,: No linkage directory; no clock available 12 SUPERVISORY LEVEL GROUP Contains all active supervisory level (S/L) groups excluding Ail Call, with the associated tributary addresses. Format: 16-bit binary unsigned number. Multiple groups may be nested with segmented. . BEGfN/END. 13 VIRTUAL GR

34、OUP Contains all active virtual groups with the associated virtual machine identifiers. Format: . FF EXTENSION 8-bit binary unsigned number in the range FOh to EFh 8-bit binary unsigned number in the range Oh to FFh Multiple groups may be nested with BEGiN/END. When necessary, the message may be seg

35、mented. Format: Indicates that the next information field name is a member of the extension set. Page 8 of t1 pages RP 163-1992 Annex A (informative) General concepts The following text contains a general explanation of some of the concepts used in the formulation of the system service message set.

36、It constitutes tutorial information, and is intended to assist in the understanding of the spec- ifications in previous portions of this practice. A.l System service tasks System service messages can affect all participants on the bus, tributaries as well as the bus controller; their effect, however

37、, differs between tributaries and the bus control- ler. Some system service messages address the bus controller only. These originate in a tributary and cause the bus controller to set up a new internat condition, or to originate further messages. Examples: ASSIGN LINKAGE DEASSIGN LINKAGE ASSIGN SUP

38、ERVISORY LEVEL GROUP DEASSIGN SUPERVISORY LEVEL GROUP ASSIGN VIRTUAL GROUP DEASSIGN VIRTUAL GROUP Other system service messages are sent by the bus con- troller to accomplish linkage tasks in tributaries. Exam- ples: VIRTUAL GROUP ATTACH VIRTUAL GROUP DISCONNECT VIRTUAL MACHINUGROUP SELECT Finally t

39、here are system service messages which accom- pany virtual machine messages from source to destination and have no practical effect on the bus controller. These are simply relayed by the bus controller. Examples: BLOCK INITIAL SEGMENT SUBSEQUENT SEGMENT Notes in the system service message list indic

40、ate the effect of the messages on the tributary and the bus con- troller respectively, and give detailed information about their effect. Messages which specify a virtual machine must carry both tributary address and virtual machine number as joint parameters. When a single virtual machine only is at

41、- tached to a tributary address, the virtual machine number defaults to zero (Ooh). A.4 Assigning linkages In order to establish a linkage it is necessary to make an entry in the linkage directory of the bus controller. Unless the bus controller is very simple (setting up linkages by thumbwheels or

42、a local keyboard only), system service messages originating in any tributary may be used to establish a linkage entry. The relevant messages are: ASSIGN LINKAGE and DEASSIGN LINKAGE Either message carries parameters which specify the trib- utary address and virtual machine number of both source and

43、destination; each such message assignsldeascigns a unidirectional linkage only, from one source to one desti- nation. In the assignment of groups the tributary address may be replaced by a supervisory level group address, andlor the virtual machine number may be replaced by a virtual group number. A

44、pplication details and examples of tributary linkage are given in SMPTE RP 139. The linkage of groups is described below. A.5 Assigning groups The operational requirement for the grouping of virtual machines may come from any individual tributary, or from an assignment virtual machine. However, only

45、 the bus controller is able to establish groups, and system service messages are required, therefore, to instruct the bus con- troller to take the necessary actions. A.6 Supervisory level groups A.2 Blocking and segmenting Information about blocking and segmenting of virtual ma- chine messages by th

46、e use of the corresponding system service messages is given in SMPTE RP 139. A.3 Addressing virtual machines Since more than one virtual machine logically may be connected to a tributary, the address of every virtual ma- chine is in two parts: - the tributary address; - the virtual machine number wh

47、ich identifies the virtual ma- chine connected to this tributary. In order to set up a controlled supervisory level group, two actions need to be taken by the assigning virtual machine: - direct the bus controller to assign a linkage between the controlling virtual machine and the newly defined supe

48、rvisory group; -direct the bus controller to assign all tributaries that are to be members of the new group. Linkage assignment is initiated by an ASSIGN LINKAGE message to the bus controller as described above, but using the desired supervisory level group address and virtual group number instead o

49、f a tributary address and virtual machine number. Page 9 of 11 pages SMPTE RP8163 92 8357401 0000324 759 RP 163-1992 Where a single virtual machine only is attached to each and every tributary within a supervisory level group, the virtual group number defaults to zero Oh). Assignment of the required tributaries to the group is initiated by multiple system service messages, using the command ASSIGN SUPERVISORY LEVEL GROUP to the bus controller. In reaction to each of these messages the bus controller generates a supervisory level GROUP ASSIGN message for the appropriate tr