User's Manual

Rev 1.3 SignalFire Telemetry
16
Options
There are two check boxes for additional logic options.
Failsafe Enabled – If this option is selected all rules must have valid data for the relay to be energized.
If one or more of the nodes times-out or does not exist the relay will be de-energized.
If this option is not selected, then a node that is not installed or fails to check in will be ignored and
the relay will be energized using logic only from the units that are active.
Latch De-Energized – If this option is selected the rules may only de-energize the relay. For the relay
to be energized again a Modbus write from a PLC to the gateway for the destination RSD stick relay
must occur. This is useful if manual intervention is required before the relay is energized after an
event. In the example above, a Modbus coil write to Slave ID 5 relay channel 1 (which is register 1) is
required to energize the relay. See the RSD Stick manual for a detailed register map.
The “Normal” state of the relay or digital output is the un-energized state and this state should be
used to set the controlled system (pump, motor,…) in the “safe” or “off” state.