Appendix A Encoder Physical Specifications
Fault Relay/General Purpose Interface (GPI) Ports
© 2015 Harmonic Inc. All rights reserved.
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Electra 9200, Rev O
Fault Relay/General Purpose Interface (GPI) Ports
Fault Relay
A contact closure is a physical connection between two platforms that defines the state of the
platform as either on or off. The Electra 9200 can signal a fault through a fault relay (contact
closure) for an external device. NMX communicates with the encoder via Ethernet and does
not use this function. The fault relay port connects to a Form C relay that can switch up to
0.25 A at 30 VDC.
The encoder energizes the fault relay during normal operation. The fault condition is indicated
in the same way as the encoder’s powered-off condition, which is with the relay de-energized.
You can use this method to correctly identify a power supply failure or loss of input power.
The labels of the fault relay connections, Normally open (NO) or Normally closed (NC),
indicate the non-fault state of the relay. In other words, when the encoder is running normally
without faults, the NO connection is open, and the NC connection is closed. When there is a
fault, the NO connection changes to closed, and the NC connection changes to open.
NOTE:
Any alarm causes the fault relay to change to the fault state. When multiple alarms
accumulate, all alarms must be resolved for the relay state to change.
GPI Ports
The GPI ports can be used for DPI input to the Electra 9200 and Ion-based encoders when a
contact closure is created. There are four GPI contacts. Each is independent and can be
provisioned to any one channel and multiple available channels.
To activate a contact closure:
1.
Insert the individual wires needed into the contacts:
The first three ports are for fault relay, while the inputs labeled 1 through 4 are GPI ports.
2.
Ground the wires to the ground pin (the last pin on the right) to activate a contact closure.
When configured in the DPI properties page of NMX, an SCTE35 message is sent out
when that pin is set to low.
.
Figure A–4: Fault Relay/GPI Ports Detail
lists the Fault Relay and GPI pinouts.
Table A–5: Fault Relay/GPI Port Pinouts
Pin
Connection
1
Fault Relay: Normally closed (NC)
2
Fault Relay: Normally open (NO)
3
Fault Relay: Common (CM)
4
GPI contact 1
(RN-05)
