
Thermalert
®
4.0 Series
Users Manual, Rev. 2.4, Jul 2021
52
5.8.5.3 Laser
This mode acts as external triggered laser switch. A transition at the trigger input from logical high level toward
logical low level will turn on or off the laser.
5.8.6 Relay Output
The relay output is used as an alarm for failsafe conditions or as a setpoint relay. The relay output can be used to
indicate an alarm state or to control external actions. The relay functionality can either be set to:
•
NO (normally open), NC (normally close)
•
PO (permanently open), PC (permanently close)
by the appropriate ASCII command. The relay PO and PC state can be used to detect wiring problems between
the sensor and the process environment.
The alarm output can be controlled by the target object temperature or the internal case temperature of the sensor.
In case of an alarm, the output switches the potential free contacts from a solid-state relay. The maximum load for
this output is 48 V / 300 mA.
If a spike voltage exceeding the absolute maximum rated value is generated between the output terminals, insert
a clamping diode in parallel to the inductive load as shown in the following circuit diagram to limit the spike voltage.
Figure 5-22: Spike Voltage Limitation for the Alarm Relay
5.8.7 Analog Out
The 12-wire model of the Thermalert 4.0 Series is an infrared thermometer with a built-in analog output to drive
analog devices. The output can be configured to output mA or V by means of software or a dedicated ASCII
command. The output is short circuit resistant.
5.8.7.1 mA Output
The Analog Out can be set to 0-20 mA or 4-20 mA output current range. Direct connection to a recording device
(e.g., chart recorder, PLC, or controller) is possible. The total analog output circuit impedance is limited to 500 Ω.
For the principle wiring, use the installation scheme below.
Figure 5-23: Wiring Analog Out as Current Output
Relay (G)
≤ 48 V
Process
Sensor
Relay (H)
A
V
DC
+
+ AO (J)
AGND (K)
GND (L)
+VDC (M)
Sensor
www.
.com
1.800.561.8187
Содержание Thermalert 4.0 Series
Страница 131: ...Thermalert 4 0 Series Users Manual Rev 2 4 Jul 2021 132 www com information itm com 1 800 561 8187...
Страница 133: ...Thermalert 4 0 Series Users Manual Rev 2 4 Jul 2021 134 www com information itm com 1 800 561 8187...
Страница 134: ...Appendix IECEx Certificate of Conformity 135 15 www com information itm com 1 800 561 8187...
Страница 135: ...Thermalert 4 0 Series Users Manual Rev 2 4 Jul 2021 136 www com information itm com 1 800 561 8187...