GUIDE TO INSTALLATION AND OPERATION
4
| HCO-1822
OUT – serial digital video outputs
The HCO-1822 provides two HD/SD SDI video outputs on BNC connectors, labeled
PGM
(program)
and
PVW
(preview). The SDI video signals conform to the SMPTE 292M and SMPTE 259M-C standards.
GPI IN and GPI OUT connectors
The rear panel of the HCO-1822 includes a GPI interface that allows control of the switch process.
When constructing and using an external GPI box, be aware of the following:
1.
The HCO-1822 card monitors the external power supply voltage on the GPI input. If the voltage is less than 4V
(per relay datasheet), an alarm will be raised.
2.
When a GPI INPUT is triggered while the card is operating in auto mode, the card changes to manual mode and
switches to the input selected by the GPI.
3.
DO NOT TRIGGER BOTH GPI INPUTS AT THE SAME TIME OR ALLOW THE TRIGGER PULSES TO
OVERLAP, AS DAMAGE TO THE RELAY MAY RESULT.
4.
A GPI trigger pulse should have a duration of at least 40 ms.
Figure 2.2 GPI trigger pulse timing
Using the GPI interface
•
Trigger the GPI-IN-1 or GPI-IN-2 pin to select that input.
•
Trigger the AUTO-IN or BYPASS-IN pin to select that mode
•
Read the GPI-OUT-1 and GPI-OUT-2 pins to identify which
output is selected
•
Read the AUTO-OUT and BYPASS-OUT pins to determine
whether either of these modes is in operation.
The four GPI connectors are laid out as shown:
Figure 2.3 GPI Connectors
WECO
connector
Pin
number
GPI direction
GPI name
P1
1
IN
GPI-IN-1
2
GND
3
IN
GPI-IN-2
P3
1
IN
AUTO-IN
2
Ex5V
3
IN
BYPASS-IN
P4
1
OUT
GPI-OUT-1
2
GND
3
OUT
GPI-OUT-2
P5
1
OUT
AUTO-OUT
2
GND
3
OUT
BYPASS-OUT
GPI IN 1
Min pulse width=40 ms
GPI IN 2
Min pulse width=40 ms
