| MECHANICAL
‘Double decker’ Crystal Vision module 266mm x 100mm (uses two frame slots)
Weight: 250g
Power consumption: 16.4 Watts
VIDEO INPUTS
Two 3Gb/s, HD or SD inputs
270Mb/s or 1.5Gb/s or 3Gb/s serial compliant to EBU 3267-E, SMPTE 259M, SMPTE 292M and SMPTE 424M
The video formats supported are 625, 525, 720p50, 720p59.94, 1080i50, 1080i59.94, 1080p50 and 1080p59.94
3Gb/s cable equalisation up to 80m using Belden 1694A. HD cable equalisation up to 140m with Belden 1694A or equivalent (approx. 100m with Belden 8281). SD cable equalisation >200m Belden 8281 or equivalent
Input return loss: -15dB for 50MHz to 1.5GHz and -10dB for 1.5GHz to 3GHz
Auto 50/59.94 and video format selection
Symmetrical switch which allows the user to select the ‘preferred’ input by means of a 2 x 2 routing grid. The input selected manually will be connected to the output unless it has a higher priority user-indicated error than the unselected input
VIDEO OUTPUTS
Two independent ports with two feeds of the main output and two feeds of the standby output using RM63 rear module
One equalised and reclocked loop-through of each input
270Mb/s or 1.5Gb/s or 3Gb/s serial compliant to EBU 3267-E, SMPTE 259M, SMPTE 292M and SMPTE 424M. Output follows the input format
Output B can be requested to be the same as Output A
Output B can be requested to be the opposite of Output A, making B a preview
RELAY BYPASS PROTECTION
The RM63 frame rear module provides relay bypass protection. An electromechanical relay switch needs power to hold the switch in one state and will revert to the other state (board bypass) on loss of power. It prevents signal loss by mechanically connecting the switch’s main input to its main output 1 on complete frame power failure or board removal
ANALOGUE REFERENCE
Tri-level syncs or analogue Black and Burst or video
3Gb/s, HD or SD source can use either type of reference
When cross-locking it is necessary for both the video input and reference to share the same frame rate
Amplitude of syncs 150mV to 600mV
Link on PCB selects 75 ohm termination or high impedance
Reference rear module loop-through available on RM63 – loop does not need Safe Switch-L 3G to be fitted as rear module has the passive circuitry required
TIMING ADJUSTMENTS
The framestore synchroniser in each input stream will ensure that both inputs to the switch are correctly timed to the external analogue reference so that there is no disruption during a switch
The synchronisers are intended to allow for inputs that are frequency-locked to the reference even if they are not co-timed
The synchronisation will occur solely at the start of frame point (the SAV of the switching line)
Safe Switch-L 3G will automatically synchronise sources between 0 and 1 frame
The timing can be fully adjusted using horizontal and vertical settings. Increasing the vertical setting will delay the output relative to the reference in increments of one line. Increasing the horizontal setting will increase this delay in increments of approx. 74ns for SD, 13.5ns for HD and 6.7ns for 3G. The output timing can be adjusted through an entire frame relative to the reference
LOSS OF REFERENCE PROTECTION
With loss of reference protection, Safe Switch-L 3G will change its timing smoothly between the reference and the inputs, keeping the output valid at all times
In normal operation the output timing is derived from the reference
If the reference is lost, Safe Switch-L 3G will switch to input 1 or (if not available or subsequently lost) input 2 as an alternative clock source, changing to the same sample/line/frame rate as the input without disrupting the output video. If the signal input is genlocked to the reference, the output will be unchanged. If not locked to the reference, the output data rate will change smoothly, slowly drifting relative to the reference and remaining in spec at all times. To avoid disruption the output timing is not changed to match the signal input
If the reference returns, the board will gently drift from the input source to line up with the reference over a period of time without disrupting the output signal
If neither input 1 nor 2 can be relied upon, the ‘crash lock to reference when reapplied’ control allows Safe Switch-L 3G to hard lock to the reference when it is present. If neither input 1 nor 2 is available as an alternative reference source, the Safe Switch-L 3G will freerun on loss of reference. If the reference is then reapplied, Safe Switch-L 3G will stay in freerun mode until a hard lock to reference occurs
DELAY THROUGH BOARD
The minimum delay through the board is approximately 2500 samples, roughly 1 line in HD/3G and 3 lines in SD. The actual delay on any signal path will depend on the respective input/output timing and the delay/timing control values
SWITCHING
Safe Switch-L 3G can be switched manually or automatically
Manual switching takes place either immediately or at the switching point described below, according to the setting of the switch timing controll
Automatic switching will occur at the switching point given in SMPTE RP168:2009 when the switch timing is set to ‘Field’ or ‘Frame’, or immediately if triggered by the input missing or input video standard fault conditions
Safe Switch-L 3G will not switch away from the user-selected source if it detects that the secondary source contains an error with equal or higher priority rating than the error detected on the user-selected source
Safe Switch-L 3G can be set to switch back automatically or by user intervention
Automatically: the board will switch back if the original input returns to a valid state. A programmable delay of between two and 120 seconds can be added to ensure the previously faulty input remains good for the selected time period
User intervention: if the board auto switches away from a faulty input it will stay on the new selection until the routing is changed by the user, or the new input becomes faulty
SIGNAL CHECKS
Safe Switch-L 3G performs checks on the following parameters (listed in order of priority) which can trigger an automatic switch or activate the GPI outputs, with the user able to select a number of parameters in any combination:
* Input missing: Based on correctly positioned valid sync words in the data stream. If a valid input is not present then an alarm will be raised
* Input video standard incorrect: If a specific video standard is selected, then an input of a different standard will be treated as an error condition
* EDH missing (SD only): No EDH packets
* EDH Full Field error (SD only): Received EDH value does not match the data
* EDH Active Picture error (SD only): Received EDH value does not match the data
* Line CRC error (3G/HD only): Received CRC value does not match the data
* Audio group 1 missing: If embedded audio group 1 is missing, an alarm is triggered
* Audio group 2 missing: If embedded audio group 2 is missing, an alarm is triggered
* Audio group 3 missing: If embedded audio group 3 is missing, an alarm is triggered
* Audio group 4 missing: If embedded audio group 4 is missing, an alarm is triggered
* Active video black: If all the luma samples within the active picture area are less than 13mV from nominal black value then an alarm will be triggered. The period of time for which the picture must remain black can be set from 2 to 120 seconds. The entire active picture must be continuously black for the full period – a single non-black sample restarts the delay period
* Active video frozen: An active picture checksum is calculated, and if it remains unchanged then the video is considered to be frozen and an alarm condition will be set. The period of time for which the picture must remain frozen can be set from 2 to 120 seconds. The entire active picture must be continuously frozen for the full period – a single non-frozen frame restarts the delay period. An adjustable threshold allows detection of frozen images that have passed through analogue links, or processing that introduces small frame-to-frame variations
* Audio silence (channels 1, 2, 3 or 4): A separate audio level checked is performed for each of the four channels in the selected group. The audio silence level setting can be selected from -48dBFS, -54dBFS, -60dBFS, -66dBFS, -72dBFS, -78dBFS, -84dBFS and -90dBFS. If the audio signal level falls below the selected level for a period of time from 2 to 120 seconds, then an alarm is triggered. All four channels share the same silence time setting. The audio on the channels must be continuously silent for the full period – a single non-silent sample restarts the delay period
Safe Switch-L 3G will also check the reference video standard
FAULT CONDITIONS
Two fault indications – Fault Indicator A and Fault Indicator B – can also be set and assigned to Statesman LEDs or GPIs
The fault indications each have their own list of chosen parameters which can be different from the auto switch selection (see SIGNAL CHECKS section for list of parameters)
Each fault indication can be assigned to a specific input, to either input, or to only become active if both inputs show a selected fault (select from input 1, input 2, either or both)
LED INDICATION OF:
Power supplies okay
Reference valid
Input 1 standard HD or SD, or Input 1 missing (two LEDs)
Input 2 standard HD or SD, or Input 2 missing (two LEDs)
Output A source routing
Output B source routing
GPI INPUT LEVELS
Active pull to ground, pulled up to 5V through 4700 ohm
GPI OUTPUT LEVELS
Electrically: Open collector transistors 30V, 270 ohm current limit resistors. Pulled up to 5V through 4700 ohm
GPI INPUTS AND OUTPUTS
12 bi-directional GPIs (available through the frame GPI connections for the two slots and also on the top board D-Type connection)
GPIs are software selectable as either inputs or outputs as required. The polarity of the GPI (active high or low) and pulse or level operation can also be configured for each individual GPI. An output configured for pulse operation will produce a pulse each time the corresponding status value changes state
Controls are provided to allow the following GPI functions, which can be allocated to any GPI connection:
GPI used as input:
Disables auto switching on selected output
Sets manual routing selection as input 1 to output A
Sets manual routing selection as input 2 to output A
Sets manual routing selection as input 1 to output B
Sets manual routing selection as input 2 to output B
Forces input 1 to output A and disables auto switching on output A
Forces input 2 to output A and disables auto switching on output A
Forces input 1 to output B and disables auto switching on output B
Forces input 2 to output B and disables auto switching on output B
Changes output A to the other input
Changes output B to the other input
GPI used as output:
Asserted if input 1 present
Asserted if input 2 present
Asserted if reference present
Asserted if output A routed to input 1
Asserted if output A routed to input 2
Asserted if output B routed to input 1
Asserted if output B routed to input 2
Asserted if output A selected to input 1 (even if routed to input 2 by auto-switch or force)
Asserted if output A selected to input 2 (even if routed to input 1 by auto-switch or force)
Asserted if output B selected to input 1 (even if routed to input 2 by auto-switch or force)
Asserted if output B selected to input 2 (even if routed to input 1 by auto-switch or force)
Asserted if fault indication A is active
Asserted if fault indication B is active
Asserted if auto switching is disabled on output A
Asserted if auto switching is disabled on output B
LOCAL CONTROL
Intuitive board edge interface with two select buttons, shaft encoder and ten character alphanumeric display
REMOTE CONTROL
RS422/485
19200 baud, 8 bits, 1 stop no parity
Control from frame active front panel and remote panel
Statesman allows control and status monitoring from any PC on a network. Statesman can be configured to ignore or create an alarm on any of the switching criteria by ticking the appropriate check boxes
SNMP monitoring and control available as a frame option |
