Ambient Background Temperature Compensation (Fa Models); Inputs And Outputs; Milliamp Output; Relay Outputs - RayTek MARATHON FA Operating Instructions Manual

Time
Normal State
6.2.11 Ambient Background Temperature Compensation (FA Models)
The FA model is capable of improving the accuracy of target temperature measurements by taking
into account the ambient, or background, temperature. This feature is useful when the target
emissivity is below 1.0 and the background temperature is not significantly lower than the target
temperature. To utilize this feature, you must enable the sensor with the background temperature
feature via the DataTemp Software.
6.3 Inputs and Outputs
6.3.1 Milliamp Output
The milliamp output is an analog output you can connect directly to a recording device (e.g., chart
recorder), PLC, or controller. The analog output resolution for all models is 0.5°C or 1°F. The mA
output can be forced to a specific value, underrange, or overrange with a 2‐ way RS485 command.
This feature is useful for testing or calibrating connected equipment.
6.3.2 Relay Outputs
The relay output is used as an alarm for failsafe conditions or as a setpoint relay, refer to section 10.2
Fail‐Safe Operation, p. 46. Relay outputs relate to the currently displayed temperature on the LED
display. The relay output can be used to indicate an alarm state or to control external actions. The
relay can be set to either NO (Normally Open) or NC (Normally Closed) with a 2‐ way RS485
command (depending on the compatibility requirements of connected equipment). The relay can be
forced on or off via the 2‐way for testing connected equipment.
6.3.3 Trigger
Peak Hold and Valley Hold can be Reset by shorting the Trigger input (labeled TRIG) to Ground
(labeled GND) for a minimum of 10 msec. This can be done either with a momentary switch or a relay.
Both Peak Hold and Valley Hold have to be set to 300.0 seconds to recognize this Reset. The Reset
signal will cause the peak or valley reading that the sensor is holding to change immediately to the
current target temperature.
Marathon Series FA/FR
Relay Changes State
Alarm Normal State
Figure 27: Deadband Example
Operation
962°C
Setpoint: 960°C
958°C
Alarm
31