NCB Protocol User manual
Contents
1. NCB Protocol Network Control Bus and RS 232 Protocol User manual Rev 7 NCB Protocol Rev 7 Nevion Support Nevion Europe Nevion USA P O Box 1020 1600 Emerson Avenue 3204 Sandefjord Norway Oxnard CA 93033 USA Support phone 1 47 33 48 99 97 Toll free North America 866 515 0811 Support phone 2 47 90 60 99 99 Outside North America 1 805 247 8560 E mail support nevion com See http www nevion com support for service hours for customer support globally Revision history Current revision of this document is the uppermost in the table below Rev Repl Date Sign Change description 7 6 2010 03 10 NBS Updated to Nevion manual template 6 5 2008 04 22 NBS Added more technical information New Chapter 2 3 and 4 5 4 2007 11 15 NBS New style Added Sublime specific information 4 3 2007 09 21 NBS Replaced MIDI by NCB where applicable 3 2 2002 09 03 NBS Replaced MIDI by NCB where applicable 2 1 2001 05 02 NBS Corrected Chapter 1 2 removing ACKNOWLEDGE etc 1 0 2001 03 01 NBS Changed baud rate from 9600 to 19200 on RS 232 communication 0 2000 10 10 TIL First release of document nevion com 2 NCB Protocol Rev 7 Contents 1 1 Important notes regarding the Network Control Protocol ccccccccccccccccccccnos 4 AS A eiceh tthe teeth seated ionil ord Seateiad loved iets tel ac ie i cea te ee d2. for use with video routers Command for acknowledge setting of video X points Header OxBn 1 0 1 1 Address Byte 2 0 Output Byte 3 0 Input Where Address can be 0 15 corresponding with level 1 16 Output is the number of the output that shall be controlled from 0 127 output 1 output 128 Input is the number of the input that shall be connected to the chosen output from 0 127 4 1 3 Output locking This command is used to lock an output A locked output cannot be switched to another input Command for locking an output nevion com 11 NCB Protocol Rev 7 Header OxEn 1 1 1 0 Address Byte 2 0 Output Byte 3 0 Ack Request A V Future use Lock Ack Request Message type 0 0 Command 0 1 Request 1 0 Acknowledge Response 1 1 Undefined Bit Usage Ack Lock unlock acknowledge from router Request Locking request AN Audio Video selection 0 Video 1 Audio Lock Locking flag O unlocked 1 locked Future use Future use set to 0 4 1 4 Router request This command is used to get information about the routers The command can be sent with four different data types one for sending a request and three for sending responses When a router receives a request it responds with three commands one for each response type and then repeating the comman
3. is already set b A matrix that recognizes its level will not re transmit the message if the output number or input number exceeds its size This does not apply to Sublime routers c A unit matrix or panel will not re transmit a message arriving at the NCB if it was re transmitted a short while ago typically 0 5 sec This is done by grabbing a message storing it for the timeout period and comparing it with new messages After the timeout period the unit will grab a new message for compare This is done to remove unwanted read unknown messages from the NCB ring d A message arriving at the RS232 will always be re transmitted unless it is a matrix and one of the cases a or b is fulfilled nevion com 4 NCB Protocol Rev 7 1 5 1 Example A single unit with no NCB connected Messages sent to the RS232 of a single unit will be returned once no matter what level or input output number the message has unless it is a matrix which recognizes one of the conditions a or b above 1 5 2 Example Several units connected by NCB Messages sent to the RS232 of a single unit will be returned once no matter what level or input output number the message has unless it is a matrix which recognizes one of the conditions a or b above If none of the cases a or b is fulfilled the message will also be transmitted on the NCB Then if any unit on the NCB ring recognizes any of the cases a b or c the message will stop at that point This
4. ES Audio 10 15 Reserved 16 Ported RS 422 Data router 17 XY oriented RS 422 Data router 18 63 Reserved nevion com 13
5. ade 4 A sec E TEE EE EEE 4 VARS AZZ Male S r aa aa a a a a ead ate ads 4 A A 4 1 5 Basic PrINCIDISS sio A is 4 TORS22 a td 5 IETEN O e E E PE EE E E E EE E ET 5 2 Message SHUT A di 6 Z 1Three Dyte Message derretir 6 2 2 TWO DYlS Messages prsni deaa eai iaka de been cece dean de dele cae ace ce ade 6 2 3 Message types in present System conociste atadas 7 PA ca ctettey E aaae abe ca tacts aah com dates ies 7 2 5 Criteria for removing MESSAGES aida arial aia 7 2 6 Stand alone panel via RS 232 ooococccccccoooaooccccnnoncnnnonnnnccnnnncnnnnnnnnnnnnrnnnnnnnnnnnnrnnnnncnnnnnnnns 8 3 VikinX Compact commands erreneren a e a E ae E E 9 3 1 Audio X p int set set cone ua N a E a E cous a e aE 9 AATA Co OE AEE E E E E E EEEE 9 33 X point Status OOUE S A AA A ern ha E a a 9 4 NCB extensions for Sublime routers 11 A COMAS cd iaa 11 nevion com 3 NCB Protocol Rev 7 1 1 Important notes regarding the Network Control Protocol 1 1 Binary Code First of all The VikinX RS 232 Protocol is not ASCII based It is a binary protocol thus it utilizes all 8 bits in each byte The strings shown on the next pages are in binary coded format Please be aware of the fact that any terminal program you may use to control a Network unit from a PC must be able to generate hexadecimal characters ASCII characters will not be accepted 1 2 Echo A matrix will reply on an X point set command with an ECHO In the case where an X point is already set no ECHO wi
6. corresponding with level 1 16 Output is the number of the output that shall be controlled ranging from 00h 7Fh representing outputs 0 127 128 outputs Input is the number of the input that shall be connected to the chosen output ranging from 00h 7Fh representing inputs 0 127 128 inputs 3 2 Video X point set Only for use with video routers Command for setting of video X points Header OxAn 1 0 1 0 Address Byte 2 0 Output Byte 3 0 Input Where Address n can be 0 15 corresponding with level 1 16 Output is the number of the output that shall be controlled ranging from 00h 7Fh representing outputs 0 127 128 outputs Input is the number of the input that shall be connected to the chosen output ranging from 00h 7Fh representing inputs 0 127 128 inputs 3 3 X point status request This command is used for status request on both audio and video routers Command for status request Header OxCn 1 1 0 0 Address Byte 2 0 No information carried here normally 00h but no function associated with it nevion com 9 NCB Protocol Rev 7 Where Address can be 0 15 corresponding with level 1 16 The requested router Audio or Video will send its X point status on NCB OUT and RS232 The same command format as for X point set is used 3 3 1 Actions Non
7. d A router will not accept more than one request on each level for each 100ms If a new request is received before this timeout no responses are transmitted and the command is not repeated This will prevent requests from looping on the bus When a router receives a response that could have been generated by itself it is not repeated When it receives a response that couldn t have been generated by itself it is repeated This will prevent responses from looping on the bus Command for router request Header OxDF 1 1 0 1 1 1 1 1 Byte 2 0 Data type AN Address Bit Usage A V _ Audio Video selection O Video 1 Audio Data type Value Type 0 Input 1 Output 2 Format 3 Request nevion com 12 NCB Protocol Byte 3 when Data type is request Rev 7 0 0 0 Byte 3 when Data type is input 0 Highest possible input number router size 1 Byte 3 when Data type is output 0 Highest possible output number router size 1 Byte 3 when Data type is format 0 Disconnect Format Disconnect Value Description 0 The router does not support disconnect 1 The router is using input 127 128 to disconnect an output Formats Format number Format description 0 Analogue Video 1 SD SDI Video 2 HD SDI Video 3 7 Reserved 8 Analogue Audio 9 A
8. e 3 3 2 Reply forwarding A video or audio router that receives a message as shown above on its level will reply with its entire X point status by means of video or audio X point messages from first till last output number After that the router will forward the status request message on the NCB There are exceptions given in Chapter 2 5 A control panel will check if shall forward or remove the message according to criteria given in Chapter 2 5 All units that regard this message as being irrelevant will check the message before removing it Criteria for removing messages are given in Chapter 2 5 nevion com 10 NCB Protocol Rev 7 4 NCB extensions for Sublime routers The following commands are added to the NCB protocol to support the extra features introduced in the VikinX Sublime router range None of these features are available with VikinX Compact routers 4 1 Commands 4 1 1 Audio X point acknowledge Only for use with audio routers Command for acknowledge setting of audio X points Header Ox8n 1 0 0 0 Address Byte 2 0 Output Byte 3 0 Input Where Address can be 0 15 corresponding with level 1 16 Output is the number of the output that shall be controlled from 0 127 output 1 output 128 Input is the number of the input that shall be connected to the chosen output from 0 127 4 1 2 Video X point acknowledge Only
9. epresents the values 0 9 while the values 10 15 are represented by the letters A F Hexadecimal notation often use the prefix Ox and sometimes the suffix h This document uses the suffix h Taking into account the just mentioned limitations we have the following legal values for headers and non headers Header legal values 80h FFh Other non headers legal values 00h 7Fh 2 1 Three byte messages Header 1 X X X X X X X Byte 2 0 X X X X X X X Byte 3 0 X X X X X X X Where X 0 or 1 Most of the message headers must have 2 following bytes thus forming a 3 byte message These headers are 80h BFh DOh FFh 2 2 Two byte messages Header 1 Xx Xx Xx Xx Xx Xx Xx Byte 2 0 X X Xx Xx Xx Xx Xx Where X 0 or 1 The following headers form the only exception from the 3 byte message structure COh CFh If such a header is received just 1 following byte is expected thus forming a 2 byte message These are used for status requests which are presented later nevion com 6 NCB Protocol Rev 7 2 3 Message types in present system The message system is designed to address up to 16 different router levels This has been achieved by using the last 4 bit block in the header to indicate which level is addressed This is applied on most message types in the basic system for the NCB wh
10. ile the more advanced amendments that has been introduced later deviate from this More details about this are given later in this document Header Message function VikinX Compact control protocol 90h 9Fh Audio X point message level 1 16 AOh AFh_ Video X point message level 1 16 COh CFh Audio Video status request FOh FFh_ THOR CP commands but also in use by Revis protocol VikinX Sublime specific additions to the protocol 80h 8Fh_ Audio X point Acknowledge message level 0 15 1 16 BOh BFh Video X point Acknowledge message level 0 15 1 16 DOh DFh_ THOR CP and Sublime commands E0h EFh_ Output locking 2 3 1 Actions A router that receives a message as shown above on its level here level means both address and video audio level will execute the routing command timely Any control panel that receives such a message on its level will update its indications LED GPI output Other units will ignore this message 2 3 2 Reply Forwarding A router that responds to the message above will forward the message if it is not identical to original status The message will be removed from the NCB if the status is identical to the original status A control panel will check if shall forward or remove the message according to criteria given in Chapter 2 5 All units that regard this message as being irrelevant will check the me
11. ll be sent If the matrix is part of a NCB system an ECHO will be sent two times Immediately after receiving the X point set command the receiving matrix will send an immediate ECHO The matrix will then wait for the command to pass the NCB system When the message has passed the entire NCB system another ECHO will be sent to indicate that all devices in the NCB system have been addressed 1 3 RS 422 Matrixes RS 422 Data Routers do not accept distribution of an input signal to several outputs An input signal can only be routed to one single output The Firmware of our RS 422 routers takes care of these limitations If an input Source is already connected to a particular output Destination any connection of this input to another output will disconnect the previous connection The router will in this case send the following message for the disconnected output Output connected to input 128 Input 128 is an internal default for the disconnect status Please see Network recommendations for use of RS 422 data routers for further information 1 4 Timeout The X point Status Request message has a timeout which means that you need to wait 1 second in between request messages 1 5 Basic principles Any message on any level that conforms to the standard arriving at either the NCB or the RS232 port will be re sent on both NCB and RS232 The only exceptions are a Amatrix that recognizes its level will not re transmit the message if the X point
12. me message as the one in the buffer is not resent within the given timeout the buffer is then emptied and the process starts as soon as a new message enters the router 2 6 Stand alone panel via RS 232 The RS 232 port does not have any regular mechanism for removing messages other than the first two criteria given above when a control panel is using a direct RS 232 connection to the router and not the usual NCB connection A special case has been developed in order to allow a single control panel be connected to a NCB router loop via a O modem RS 232 cable Rx Tx crossed The single control panel must not have any NCB connected in order for this to work If an NCB loop were connected to the control panel in addition to the direct RS 232 connection between panel and router s messages on the RS 232 port would not generate any echo If the panel senses a valid message on its NCB port it goes into normal operation and generates an echo on the RS 232 port Messages will then jump back and forth between the two NCB loops infinitely thus blocking the communication 3 Only applicable to Sublime routers and Triton routers nevion com 8 NCB Protocol Rev 7 3 VikinX Compact commands 3 1 Audio X point set Only for use with audio routers Command for setting of audio X points Header Ox9n 1 0 0 1 Address Byte 2 0 Output Byte 3 0 Input Where Address n can be 0 15
13. means that the message will only be returned once on the RS232 However if none of the units on the NCB ring recognizes any of the cases a to c the message will return to the originator the unit which received the message on RS232 This unit will re transmit the message once more on both NCB and RS232 The message is therefore returned a second time on RS232 This time one of the cases a or c is sure to be identified by one of the units on the NCB ring and the message is removed There is however one more special case If several messages for unused levels are transmitted with only little delay one might experience that some messages are returned several times as the store compare remove function in case c can only handle a single message at the time We therefore recommend that the user avoid sending messages to unused levels 1 6 RS232 The RS 232 port is used for external control of Network units The RS 232 port allows the customer to control the equipment via Multicon or self defined customized solutions Connector for the RS 232 port is a DS9 female Pin 2 Tx Pin 3 Rx Pin 5 GND A standard DCE Data Communication Equipment cable can be used for connection between PC and Network equipment The connection between the connectors is made one to one Data rate is 19200 baud sec 8 data bit 1 stop bit no parity 1 7 NCB The NCB is used for interconnection between several Network units Up to 50 routers and o
14. move this command and not forwarding it There will not be sent an echo either if it receives such a message directly via RS 232 The same happens if the message contains an input or output number that is higher than what is defined for the router thus an illegal command Any router has a built in timeout for status requests When the router has sent its status it will not accept a new status request before a certain time has elapsed The new status request message is removed if it comes within this timeout Analogous if this request is sent directly to the current router via RS 232 neither any echo nor any other response will be sent This timeout is 1 second for VikinX products All units have a buffer for messages in order to check for fast repeating messages This buffer can only contain 1 single message at a time and the buffer is emptied after a certain time This timeout is approximately 100ms The message check buffer is only applicable on the NCB and not on the RS 232 port As soon as the buffer is empty the next message that is received by the router will be buffered for the given timeout before it is forwarded on the NCB All new messages are compared to this buffered message as long as the timeout is active If the same message as the one in the buffer is resent within this timeout it will be removed and not forwarded The buffer is then emptied and the process starts as soon as a new message enters the router If the sa
15. r control panels can be linked together to form a routing system with many operational features The NCB utilizes a 5 mA current loop with opto coupled ports Standard connector is RJ45 Standard MIDI cables can be used to interconnect several Network units Data rate is 31 25 Kbps 1 start bit 8 data bit no parity 1 stop bit Logical O current ON 1 Or ETH CON See www nevion com for options nevion com 5 NCB Protocol Rev 7 2 Message structure The basic structure of the protocol is adapted from MIDI in conformity with the physical interface of the bus connection But except from that the protocol is not a full MIDI protocol It will be possible to let a MIDI sequencer run control of the routers via MIDI but apart from that NCB is not compatible to the MIDI standard Mainly a 3 byte message is used but sometimes a 2 byte message is used The first byte in a message is always a header The difference from the other bytes is that bit 7 msb most significant bit is set high 1 Only the header byte must have msb set high the other bytes must have msb set low 0 The way the system is designed it is easy to detect the start of a new message as only the header may have msb 1 We usually note the messages in a hexadecimal notation where each byte is divided into two 4 bit blocks each block may thus have a value between O and 15 This value is translated into a character The corresponding numbers r
16. ssage before removing it Criteria for removing messages are given in Chapter 2 5 2 4 Unknown messages Any message that confirms to the general 3 byte message or 2 byte message structure but which is not recognized by any of the devices in the NCB loop will be ignored and forwarded after a check if the message must be removed according to criteria given in Chapter 2 5 Messages that do not confirm to the general structure will be removed regardless or will be shortened according to the 3 byte 2 byte structure if they are too long 2 5 Criteria for removing messages Because the NCB loop is a closed loop where the messages pass in ring it is essential that superfluous messages be removed as soon as possible The following set of criteria for removing messages is a made in order to avoid unnecessary traffic on the bus see also Chapter 1 5 The only two byte message type nevion com 7 NCB Protocol Rev 7 Routers remove X point commands that are already executed A status request message is not accepted too short after the previous status request Any unit may remove repeating messages within short time The device that generated the message X point Acknowledge removes it when the message has passed the NCB loop Further explanation A router that receives an X point command on its level here level means both address and video audio level that corresponds to its present status will always re
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