5700ACO
Automatic Changeover
Revision 1.0 Page 1
1. OVERVIEW
The 5700ACO Automatic Changeover is intended to be connected directly to two 5700MSC-IP
Master Clock / Sync Generators (Figure 2-2). The 5700ACO system uses latching relays to ensure
maximum reliability and minimal disruption in the event of any failure. The complete system provides
the highest level of security for television station video and time synchronization systems. Two power
supplies are included as a standard feature, to alleviate any single point of failure concerns.
The above recommended practices provide the highest degree of protection by minimizing the number
of point of failure connections within your plant referencing system. If you wish to modify your
referencing system from the recommended design, please consult the factory prior to implementation to
ensure your system’s maximum reliability is maintained.
The front panel has one pushbutton. This button shows the last state which caused a changeover. This
is to assist with diagnostics in cases where the problem has cleared before an operator can observe
the front panel. Seventy LEDs provide status information as to the health of the two 5700MSC-IPs
together with indication as to which one is active. In addition two GPO outputs indicate which master is
active and when the inputs from both masters are not the same.
The main circuit board has three switches, behind the front panel for added security. There is an
AUTO / MANUAL switch, a GPI / FRONT PANEL switch and an A / B select switch for manual
changeover. In automatic mode, all signals from both 5700MSC-IPs are scrutinized to detect any
abnormal signals. For example if a level, pulse width, phase, time code error or other abnormality is
detected, the 5700ACO circuitry will trigger and the entire bank of signals will be switched to the backup
5700MSC-IP. In manual mode the changeover can be operated from a GPI or from the front panel
switch.
The 5700ACO features selectable voting via VistaLINK
®
for auto-changeover feature. Individual inputs
may selectively be included or excluded in the voting process to drive auto-changeover logic.
The 5700ACO offers connections for 6 colour black, (or bi-level or tri-level sync signals, or 10 MHz or
pulses or word clock), 1 10MHz , 1 Word clock, 8 SD/HD/3G SDI test signals, DARS, 2 AES, analog
audio, and two linear time codes (LTC) to each of the two Master 5700MSC-IPs. Each 5700MSC-IP
Master offers two LTC outputs that may be used for different time codes. All four LTC signals are fed to
the 5700ACO on two 'D' connectors, one for each Master. The LTC outputs from the selected master
are available on two XLR connectors. There is an XLR for LTC input which will feed this signal to both
5700MSC-IPs. The Word clock and 10 MHz inputs can also monitor bi-level, tri-level sync signals.
Each 5700MSC-IP provides 2 GPO signals which are also on the ‘D’ connectors. The 5700ACO feeds
these signals through to the 2 x 8 terminal blocks. Each 5700MSC-IP is equipped with 2 GPI inputs and
2 GPO outputs. To facilitate installation, these connections are connected through to a 2 x 8 pin
terminal block on the 5700ACO. The outputs from the 5700MSC-IP s are passed straight through the
5700ACO. The 5700ACO can monitor these signals and include them in the decision making process.
Inputs to the 5700MSC-IPs are internally split by a 'Y' connector to ensure that both 5700MSC-IPs
receive the same GPI contact closures.
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