SMPTE RP 191-1996 Routing Switcher Type-Specific Messages for Remote Control of Broadcast Equipment.pdf
《SMPTE RP 191-1996 Routing Switcher Type-Specific Messages for Remote Control of Broadcast Equipment.pdf》由会员分享,可在线阅读,更多相关《SMPTE RP 191-1996 Routing Switcher Type-Specific Messages for Remote Control of Broadcast Equipment.pdf(19页珍藏版)》请在麦多课文档分享上搜索。
1、SMPTE RP*ll b 8357403 0002445 349 H RP 191-1996 SMPTE RECOMMENDED PRACTICE Routing Switcher Type-Specific Messages for Remote Control of Broadcast Equipment Introduction This clause contains a general explanation of some of the concepts used in the formulation of the routing switcher type-specific m
2、essage set. It constitutes tutorial information and is intended to assist in the understanding of the specifications in clause 6 of this practice. A working knowledge of the following ESbus topics is assumed: - ESbus system overview; - control message architecture; - supervisory protocol; - tributar
3、y interconnection; - electrical and mechanical characteristics; - system service and common messages. Conventions: Acronyms and abbreviations are shown in uppercase characters; e.g., information field - IF. Message keywords and names of information fields are shown in uppercase characters; e.g., CON
4、NECT CROSSPOINT; SOURCE POINTER. These command keywords and information field names are used within the text of this practice to imply requested action, information field identity, and, in turn, the information field contents of the virtual machine. To assist in readability of this practice, these t
5、erms are used in the context of the presentation material; e.g., “If this I/F is PRESET, ” (PRESET in this context refers to a command contained within the type-specific message set.) Terms with special meaning to this or related docu- ments are shown with leading uppercase characters; e.g., Virtual
6、 Machine; Common Messages. Page 1 of 19 pages 1 Scope of the dialect This dialect is intended to be used for the external control of routing switcher systems. 2 Multidimensional information fields The controlled elements in a routing switcher are in the crosspoints. The crosspoints are arranged in a
7、 multidimensional way; .e., to identify an individual crosspoint, it is usually necessary to specify the following characteristics of its location: - its row (1 .dimension); - its column (2.dimension); - its level (3.dimension); - its matrix (4.dimension). (The latter applies only to a switcher cons
8、isting of several matrices.) In ESbus dialects, all kinds of status data are main- tained in Information Fields (VFs). Each type of infor- mation has its corresponding I/F associated with a unique I/F Name. In routing switcher systems, nearly all status data are related to crosspoints. Because cross
9、points are arranged in a multidimensional way, and each crosspoint is the carrier of status data, the I/Fs describing routing switcher data must also be multidimensional. The particular item of information belonging to one crosspoint is just an element of the whole Information Field of acertain type
10、. This requires additional descriptors which point to the location of this element within the field; .e., to the row, column, level, and matrix. When such an element of an I/F is tallied, these descriptors are simply carried as parameters in the format. When such an element is accessed, however, Cop
11、yright O 1996 by the SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved September 1,1996 SUPTE RP*LL 96 357403 O002446 085 W RP 191-1996 a different mechanism is required due to the fact that the Common commands which access I/Fs
12、(e.g., READ, UPDATE, CYCLE) allow only for specifying the I/F name. No additional descriptor information is permitted in the format. Such additional information must, therefore, be transmitted in advance by pre- setting one or more pointers which predefine the parameters necessary for multidimension
13、al access. The pointers themselves also reside in Information Fields of their own and thus can be PRESET as any other presettable I/F. This gives the advantage that the pointer information need only be transmitted when it really changes, not in advance of every I/F access. The names of the relevant
14、pointers are: - MATRIX POINTER; - LEVEL POINTER; - SOURCE POINTER; - DESTINATION POINTER. NOTE - In order to PRESET a multidimensional VF, no pointers are required since the whole format of an I/F appears within the PRESET command, including the descriptors. Because of special requirements of routin
15、g switchers, one of these dimensions may not be specified; e.g., the I/F DESTINATIONS-TO-SOURCE does not use the DESTINATION POINTER because it shows all connections between a specified source and any destination in the form of a list. 3 Wildcard characters In order to facilitate access to a whole a
16、rray (row, column, level, matrix) of one type of a multi- dimensional status information, a wildcard character is introduced (FFh to FFFFh, respectively). A pointer, preset to the wildcard, indicates (when an I/F access requiring this pointer is made) that the information corresponding to the full a
17、vailable range of the pointer is desired. For example, if the LEVEL POINTER is preset to FFh, a subsequent READ of the I/F CROSSPOINT STATUS will result in a multiple I/F RESPONSE message (either in many single messages or in one message using the BEGIN/END construct or in combination) tallying the
18、crosspoint status of all existing levels. A second application of the wildcard concerns certain commands (e.g., CONNECT CROSSPOINT), where it can be used as a normal parameter with the same effect. The description of the commands and information fields in clause 6 contains detailed instructions as t
19、o when and how wildcards can be used. 4 Procedures and events As with all Dialects, the complete Routing Switcher Dialect, by definition, consists of both Common Mes- sages and the Routing Switcher Type-Specific Dialect described in this practice. The elements of the Common Messages prove very usefu
20、l for switcher applications and are, there- fore, recommended. The concept of Procedures provided by the common messages can be used to predefine a lengthy set of commands (by the DEFINE PROCEDURE command) pending the arrival of the EXECUTIVE PROCEDURE command, which causes the entire Procedure to b
21、e performed. The concept of Events provided by the Common Messages can be used to predefine a command (by the DEFINE EVENT command) to be executed at a certain point in time. As the time scale (usually the Timeline) is used, an individual software clock running in each controlled Virtual Machine is
22、preset by the bus controller (by the System Service command REQUEST TIME TRANSMISSION). Both concepts can easily be combed by first defining a procedure, then defining an event with EXECUTE PROCEDURE as the command to be carried out on the timeline. Details about these facilities are described in th
23、e documents about System Service and Common Messages mentioned above. 5 Sample command sequences The following message sequences show the applica- tion of the dialect (including the Common Messages). The commands are also shown encoded into their hexadecimal codes. The PRESET commands signed with a
24、“ sign may be omitted if the corresponding I/F has already been preset by a preceding PRESET command. Page 2 of 19 pages SMPTE RP*191 96 8357403 0002447 TIL = RP 191-1996 5.1 Disconnecting all crosspoints in level #1 O matrix #2: 5.2 Requesting the status of all crocspoints in level #2 of matrix #1:
- 1.请仔细阅读文档,确保文档完整性,对于不预览、不比对内容而直接下载带来的问题本站不予受理。
- 2.下载的文档,不会出现我们的网址水印。
- 3、该文档所得收入(下载+内容+预览)归上传者、原创作者;如果您是本文档原作者,请点此认领!既往收益都归您。
下载文档到电脑,查找使用更方便
10000 积分 0人已下载
下载 | 加入VIP,交流精品资源 |
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- SMPTERP1911996ROUTINGSWITCHERTYPESPECIFICMESSAGESFORREMOTECONTROLOFBROADCASTEQUIPMENTPDF

链接地址:http://www.mydoc123.com/p-1046424.html